Functional weakness and sensory disturbance

Outpatient Rehabilitation of a Patient with Functional Neurological Disorder Receiving Workers' Compensation Benefits: A Case Report

Background

Functional neurological disorder (FND) is a clinical syndrome characterized by abnormal involuntary movements and specific clinical features that are incongruent with known neurologic diseases. Clinical information is lacking on outpatient rehabilitation for patients with FND.

Case

A 28-year-old woman visited our hospital for gait disturbance. She had experienced an occupational accident 20 months earlier. Her injuries were relatively minor, but subsequently, she was unable to move her ankle voluntarily and began receiving workers' compensation benefits. The patient had persistent gait disturbance and preferred to walk with an ankle-foot orthosis. However, at her first visit, her ankle could move while walking without her ankle brace. Nerve conduction studies showed no abnormalities. Shortly after receiving an explanation regarding the diagnosis of FND, the patient was able to move her ankle voluntarily; however, her gait disturbance was partially persistent. After outpatient rehabilitation, she was able to walk in different types of footwear without an ankle brace. Satisfied with the result, she agreed to end rehabilitation and her access to workers' compensation.

Discussion

After diagnosis and rehabilitation for FND following an occupational injury, our patient was eventually able to walk without an ankle brace. In this case, providing the patient with information regarding a diagnosis of FND and obtaining her informed consent for subsequent rehabilitation may have helped to improve the symptoms of FND.

Weak gluteus maximus and weak iliopsoas with normal gluteus maximus: Two complementary new signs to diagnose lower limb functional weakness

BACKGROUND AND PURPOSE

The diagnosis of functional neurological disorder should be actively made based on the neurological signs. We described two new complementary signs to diagnose functional weakness of the lower limb, "weak gluteus maximus (weak GM)" and "weak Iliopsoas with normal gluteus maximus (weak iliopsoas with normal GM)," and tested their validity.

METHODS

The tests comprised Medical Research Council (MRC) examinations of the iliopsoas and GM in the supine position. We retrospectively enrolled patients with functional weakness (FW) or structural weakness (SW) who presented with weakness of either iliopsoas or GM, or both. Weak GM means that the MRC score of GM is 4 or less. Its complementary sign, weak ilopsoas with normal GM, means that the MRC score of ilopsoas is 4 or less, whereas that of GM is 5.

RESULTS

Thirty-one patients with FW and 72 patients with SW were enrolled. The weak GM sign was positive in all 31 patients with FW and in 11 patients with SW, that is, 100% sensitivity and 85% specificity. Therefore, the complementary sign, weak iliopsoas with normal GM, was 100% specific for SW.

DISCUSSION

Although 100% should be discounted considering limitations of this study, these signs will likely be helpful in differentiating between FW and SW in the general neurology setting. Downward pressing of the lower limb to the bed in the supine position is interpreted by the patient as an active movement exerted with an effort and might be preferentially impaired in FW.

Diagnosis of psychogenic (functional) gait disorders

Psychogenic gait is common in patients with medically unexplained neurological symptoms and provides significant challenges to healthcare providers. Clinicians may arrive at a correct diagnosis earlier if distinctive positive signs are identified and acknowledged. Psychogenic disorders of posture and gait are common and are the major manifestation in 8–10 % of patients with psychogenic movement disorders. Psychogenic movement disorders can present with varied phenomenology that may resemble organic movement disorders. The diagnosis is based on clinical evaluation with a supporting history and classic features on neurologic examination. In functional gait disorders, walking is often bizarre and does not conform to any of the usual patterns observed with neurologic gait disorders. Astasia-abasia, an inability to stand (astasia) or walk (abasia) in the absence of other neurologic abnormalities, was the term applied by investigators in the mid to late 19thcentury to describe certain patients with a frankly functional gait. Other descriptive terms include gaits that resemble walking on ice, walking a sticky surface, walking through water (bringing to mind excessive slowness), tightrope walking, habitual limping, and bizarre, robotic, knock-kneed, trepidant, anxious, and cautious gaits. Ancillary testing, such as imaging and neurophysiologic studies, can provide supplementary information but is not necessary for diagnosis. 

Why functional neurological disorder is not feigning or malingering

Functional neurological disorder (FND) is one of the commonest reasons that people seek help from a neurologist and is for many people a lifelong cause of disability and impaired quality of life. Although the evidence base regarding FND pathophysiology, treatment and service development has grown substantially in recent years, a persistent ambivalence remains amongst health professionals and others as to the veracity of symptom reporting in those with FND and whether the symptoms are not, in the end, just the same as feigned symptoms or malingering. Here, we provide our perspective on the range of evidence available, which in our view provides a clear separation between FND and feigning and malingering. We hope this will provide a further important step forward in the clinical and academic approach to people with FND, leading to improved attitudes, knowledge, treatments, care pathways and outcomes.

Functional Neurological Disorders: Clinical Spectrum, Diagnosis, and Treatment

BACKGROUND

Functional neurological disorders (FNDs) are common but often misdiagnosed.

REVIEW SUMMARY

The incidence of FNDs is between 4 and 12 per 100,000, comparable to multiple sclerosis and amyotrophic lateral sclerosis, and it is the second most common diagnosis in neurology clinics. Some clues in the history are sudden onset, intermittent time course, variability of manifestation over time, childhood trauma, and history of other somatic symptoms. Anxiety and depression are common, but not necessarily more than in the general population. Although there are no tests currently capable of demonstrating whether symptoms are willfully produced, there may not be a clear categorical difference between voluntary and involuntary symptoms. The prognosis of an FND is linked to early diagnosis and symptom duration, but unfortunately, the majority of the patients are diagnosed after considerable delays.

CONCLUSIONS

A positive diagnosis of FNDs can be made on the basis of history and neurological signs without reliance on psychological stressors. Past sensitizing events and neurobiological abnormalities contribute to the pathogenesis of FNDs. Physical rehabilitation and psychological interventions alone or in combination are helpful in the treatment.

Diagnosis of Functional Weakness and Functional Gait Disorders in Children and Adolescents

Functional neurological disorder is neurological dysfunction not primarily explained by pathophysiologic or structural abnormalities and can present in children and adolescents with limb weakness, gait abnormality, non-epileptic seizures or sensory changes. In this review article we focus primarily on the diagnosis of functional limb weakness and functional gait disorders, and how to differentiate functional neurological disorders from structural or pathologic neurological presentations of weakness or gait disturbance. Detailed history and attentive observation of a patient outside of the formal neurological examination can be pertinent to identifying inconsistency and incongruency in keeping with functional neurological presentations. Understanding of structural and physiologic neurological pathology is required to identify non-anatomical and non-pathological features consistent with a diagnosis of functional neurological disorder. Diagnosis is made on recognition of positive clinical features of a functional disorder on examination and is not based primarily on exclusion of a pathologic neurological disorder. Specific tests can be performed to elicit pathognomonic findings supportive of a diagnosis of functional limb weakness and gait disorders.

Hemisensory syndrome: Hyperacute symptom onset and age differentiates ischemic stroke from other aetiologies

Background

An important cause of hemisensory syndrome is ischemic stroke. However, the diagnostic yield of neuroradiological imaging on hemisensory syndrome is low. Therefore, we aim to describe patients hospitalized with isolated hemisensory syndrome, and to identify clinical features associated with an aetiology of ischemic stroke.

Methods

We performed a single centre retrospective observation study, identifying patients who were hospitalised with hemisensory syndrome from October 2015 to March 2016, and whom underwent a magnetic resonance imaging (MRI) brain during the admission. Ischemic stroke was defined as the presence of restricted diffusion-weighted image on the MRI brain. Clinical information was analysed and compared between patients with and without stroke seen on MRI brain.

Results

79 patients, 36 (45.6%) males and 43 (54.4%) females, aged between 30 to 87 years (mean 54), were included in the final analysis. 18 (22.8%) patients were identified to have an acute ischemic stroke. Clinical features associated with ischemic stroke in hospitalised patients with hemisensory syndrome include symptom onset of ≤24 h at presentation (odds ratio 31.4, 95% CI 3.89–254.4), advanced age (odds ratio 1.14, CI 1.05–1.25) and smoking (odds ratio 7.35, 95% CI 1.20–45).

Conclusion

Older patients, with a history of smoking, and who present with an acute onset of symptoms, are more likely to have ischemic stroke as the cause of their hemisensory syndrome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02206-8.

What is the functional/organic distinction actually doing in psychiatry and neurology?

The functional-organic distinction aims to distinguish symptoms, signs, and syndromes that can be explained by diagnosable biological changes, from those that cannot. The distinction is central to clinical practice and is a key organising principle in diagnostic systems. Following a pragmatist approach that examines meaning through use, we examine how the functional-organic distinction is deployed and conceptualised in psychiatry and neurology. We note that the conceptual scope of the terms 'functional' and 'organic' varies considerably by context. Techniques for differentially diagnosing 'functional' and 'organic' diverge in the strength of evidence they produce as a necessary function of the syndrome in question. Clinicians do not agree on the meaning of the terms and report using them strategically. The distinction often relies on an implied model of 'zero sum' causality and encourages classification of syndromes into discrete 'functional' and 'organic' versions. Although this clearly applies in some instances, this is often in contrast to our best scientific understanding of neuropsychiatric disorders as arising from a dynamic interaction between personal, social and neuropathological factors. We also note 'functional' and 'organic' have loaded social meanings, creating the potential for social disempowerment. Given this, we argue for a better understanding of how strategic simplification and complex scientific reality limit each other in neuropsychiatric thinking. We also note that the contribution of people who experience the interaction between 'functional' and 'organic' factors has rarely informed the validity of this distinction and the dilemmas arising from it, and we highlight this as a research priority.

['Stroke chameleons']

The diagnosis of acute stroke should be correct and early that allows physician planning the most effective treatment strategies (reperfusion therapy, undifferentiated (basic) treatment, early secondary prevention). However, stroke symptoms can be atypical and similar to some other (non-vascular) event. It can significantly complicate the clinical diagnosis of stroke and decrease the patient's chances for effective treatment. A stroke should be suspected in every patient with acute onset of neurological symptoms, especially when the patient has the 'vascular' risk factors. Furthermore it is important to remember that negative CT-scan data and/or MRI data do not exclude the presence of not only ischemic stroke but also hemorrhagic stroke. The article describes the main variants of strokes with atypical symptoms (strokes-chameleons), emphasizes the importance of careful clinical examination, provides supportive differential diagnostic criteria and discusses limitations of neuroimaging methods.

Functional Neurologic Symptom Disorder in Children: Clinical Features, Diagnostic Investigations, and Outcomes at a Tertiary Care Children's Hospital

OBJECTIVE

To describe the presenting symptoms and short-term outcomes of children diagnosed with functional neurologic symptom disorder and to compare the demographic and clinical characteristics of children who received neurodiagnostic testing to those who did not.

STUDY DESIGN

Single center, retrospective review of 222 children who presented to the emergency department of a children's hospital, and diagnosed with functional neurologic symptom disorder, between 2010 and 2015.

RESULTS

Out of 222 visits (females = 156, African Americans = 130, mean age = 13.9 years), neurodiagnostic tests were performed in 102/222 (46%) visits. The most commonly performed investigations were magnetic resonance imaging (MRI) of brain (n = 37) and electroencephalogram (EEG) (n = 56) and were noted to be unremarkable in all instances. Neurodiagnostic tests were more likely to be performed in patients who (1) were non-African American (54% vs 40%; P = .03), (2) presented with new-onset symptoms (55% vs 31%; P < .01), (3) underwent hospitalization (61% vs 17%; P < .01), and (4) were evaluated by a neurologist (59% vs 9%; P < .01) or a psychiatrist (58% vs 28%; P < .01). Common clinical presentations included seizurelike or strokelike symptoms. Short-term follow-up was possible in 20%, with an alternate diagnosis of syncope, noted in only 1 child.

CONCLUSIONS

Most children who presented with a functional neurologic symptom disorder in our study were noted to have seizurelike or strokelike presentations and were adolescent females. Caucasians were more likely to undergo neurodiagnostic investigations. Radiologic and neurophysiological tests were more commonly performed when neurology and psychiatry consultations were sought. Such investigations had low diagnostic utility.

Positive clinical signs in neurological diseases - An observational study

Many patients with organic neurological disease have symptoms and signs that are unexplained by their disease condition. We attempted to explore the prevalence of positive clinical signs in patients with various organic neurological diseases. We performed a prospective uncontrolled observational study on the presence of 7 positive signs in adults with various organic neurological diseases that were admitted to our tertiary care hospital. This observation was performed during their neurological examination in those who provided consent, could comprehend and lacked terminal illness or profound weakness that limited their ability to perform these tasks. We dichotomized them into two groups based on the presence of these signs. Out of 190 patients that were evaluated between 2014 and 2015, 37 patients had at least one positive sign. On univariate analysis: young age, female gender, prior anxiety, history of childhood abuse, identification of sensory deficits on examination and lack of imaging correlation with clinical localization were identified as risk factors for these positive signs. On multivariate analysis, anxiety (OR 2.88, 95% CI 1.11-7.49, p = 0.03) and presence of sensory deficits on examination (OR 5.81, 95% CI 2.36-14.32, p ≤ 0.001) were associated with these positive signs. Positive signs are common in patients with organic neurological diseases that have anxiety or sensory deficits and may imply a component of functional overlay. Large studies are required to understand its pathophysiology and impact on future outcomes.

Somatosensory deficits

The analysis and interpretation of somatosensory information are performed by a complex network of brain areas located mainly in the parietal cortex. Somatosensory deficits are therefore a common impairment following lesions of the parietal lobe. This chapter summarizes the clinical presentation, examination, prognosis, and therapy of sensory deficits, along with current knowledge about the anatomy and function of the somatosensory system. We start by reviewing how somatosensory signals are transmitted to and processed by the parietal lobe, along with the anatomic and functional features of the somatosensory system. In this context, we highlight the importance of the thalamus for processing somatosensory information in the parietal lobe. We discuss typical patterns of somatosensory deficits, their clinical examination, and how they can be differentiated through a careful neurologic examination that allows the investigator to deduce the location and size of the underlying lesion. In the context of adaption and rehabilitation of somatosensory functions, we delineate the importance of somatosensory information for motor performance and the prognostic evaluation of somatosensory deficits. Finally, we review current rehabilitation approaches for directing cortical reorganization in the appropriate direction and highlight some challenging questions that are unexplored in the field.

Stroke Chameleons and Stroke Mimics in the Emergency Department

PURPOSE OF REVIEW

We discuss the frequency of stroke misdiagnosis in the emergency department (ED), identify common diagnostic pitfalls, describe strategies to reduce diagnostic error, and detail ongoing research.

RECENT FINDINGS

The National Academy of Medicine has re-defined and highlighted the importance of diagnostic errors for patient safety. Recent rates of stroke under-diagnosis (false-negative cases, "stroke chameleons") range from 2-26% and 30-43% for stroke over-diagnosis (false-positive cases, "stroke mimics"). Failure to diagnosis stroke can preclude time-sensitive treatments and has been associated with poor outcomes. Strategies have been developed to improve detection of posterior circulation stroke syndromes, but ongoing work is needed to reduce under-diagnosis in other atypical stroke presentations. The published rates of harm associated with stroke over-diagnosis, particularly thrombolysis of stroke mimics, remain low. Additional strategies to improve the accuracy of stroke diagnosis should focus on rapid clinical reasoning in the time-sensitive setting of acute ischemic stroke and identifying imperfections in the healthcare system which may contribute to diagnostic error.

Testing Head Rotation and Flexion Is Useful in Functional Limb Weakness

Background

Functional (psychogenic) neurological disorders (FNDs) are common and should be diagnosed using positive diagnostic features of internal inconsistency. However, there is a lack of objective data regarding motor signs and a lack of signs relating to motor disorders that affect the upper body and neck. The objective of this study was to provide specificity and sensitivity data on 2 axial motor signs: the sternocleidomastoid (SCM) and platysma signs.

Methods

Thirty patients with motor FNDs according to the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, and 40 organic controls with unilateral weakness were prospectively included. The SCM functional sign and platysma organic signs were systematically tested and compared between groups.

Results

The SCM sign had high specificity of 90% (confidence interval [CI], 77%-96%) to detect FND when the platysma sign had 100% specificity (CI, 88%-100%) for detecting organic weakness. The co-occurrence of a positive SCM and a negative platysma sign in patients with unilateral weakness carried 95% specificity (CI, 83%-99%) and 63% sensitivity (CI, 44%-80%).

Conclusion

The SCM test and platysma signs can be used for the diagnosis of motor FND. The extent to which these add value to other validated signs (such as Hoover's sign) should be further evaluated.

Neurologic diagnostic criteria for functional neurologic disorders

The diagnosis of functional neurologic disorders can be challenging. In this chapter we review the diagnostic criteria and rating scales reported for functional/psychogenic sensorimotor disturbances, psychogenic nonepileptic seizures (PNES) and functional movement disorders (FMD). A recently published scale for sensorimotor signs has some limitations, but may help in the diagnosis, and four motor and two sensory signs have been reported as highly reliable. There is good evidence using eight specific signs for the differentiation of PNES from seizures. Recently, diagnostic criteria were developed for PNES; their sensitivity and specificity need to be evaluated. The definitive diagnosis of PNES can be made by recording typical positive features during the spells, and in a low proportion of cases, where the distinction with an organic etiology cannot easily be done, a normal electroencephalogram suggests the diagnosis. FMD diagnosis relies on diagnostic criteria, which have been refined over time and may be supplemented by laboratory tests in some phenotypes. Rating scales for PNES and FMD could be useful for severity measures, but several limitations remain to be addressed.

Validity assessment and the neurological physical examination

BACKGROUND

The assessment of any patient or examinee with neurological impairment, whether acquired or congenital, provides a key set of data points in the context of developing accurate diagnostic impressions and implementing an appropriate neurorehabilitation program. As part of that assessment, the neurological physical exam is an extremely important component of the overall neurological assessment.

PURPOSE

In the aforementioned context, clinicians often are confounded by unusual, atypical or unexplainable physical exam findings that bring into question the organicity, veracity, and/or underlying cause of the observed clinical presentation. The purpose of this review is to provide readers with general directions and specific caveats regarding validity assessment in the context of the neurological physical exam.

CONCLUSIONS

It is of utmost importance for health care practitioners to be aware of assessment methodologies that may assist in determining the validity of the neurological physical exam and differentiating organic from non-organic/functional impairments. Maybe more importantly, the limitations of many commonly used strategies for assessment of non-organicity should be recognized and consider prior to labeling observed physical findings on neurological exam as non-organic or functional.

An integrative neurocircuit perspective on psychogenic nonepileptic seizures and functional movement disorders: neural functional unawareness

Functional neurological disorder (conversion disorder) is a neurobehavioral condition frequently encountered by neurologists. Psychogenic nonepileptic seizure (PNES) and functional movement disorder (FMD) patients present to epileptologists and movement disorder specialists respectively, yet neurologists lack a neurobiological perspective through which to understand these enigmatic groups. Observational research studies suggest that PNES and FMD may represent variants of similar (or the same) conditions given that both groups exhibit a female predominance, have increased prevalence of mood-anxiety disorders, frequently endorse prior abuse, and share phenotypic characteristics. In this perspective article, neuroimaging studies in PNES and FMD are reviewed, and discussed using studies of emotional dysregulation, dissociation and psychological trauma in the context of motor control. Convergent neuroimaging findings implicate alterations in brain circuits mediating emotional expression, regulation and awareness (anterior cingulate and ventromedial prefrontal cortices, insula, amygdala, vermis), cognitive control and motor inhibition (dorsal anterior cingulate, dorsolateral prefrontal, inferior frontal cortices), self-referential processing and perceptual awareness (posterior parietal cortex, temporoparietal junction), and motor planning and coordination (supplementary motor area, cerebellum). Striatal-thalamic components of prefrontal-parietal networks may also play a role in pathophysiology. Aberrant medial prefrontal and amygdalar neuroplastic changes mediated by chronic stress may facilitate the development of functional neurological symptoms in a subset of patients. Improved biological understanding of PNES and FMD will likely reduce stigma and aid the identification of neuroimaging biomarkers guiding treatment development, selection, and prognosis. Additional research should investigate neurocircuit abnormalities within and across functional neurological disorder subtypes, as well as compare PNES and FMD with mood-anxiety-dissociative disorders.

Large-field repetitive transcranial magnetic stimulation with circular coil in the treatment of functional neurological symptoms

OBJECTIVE

Patients with functional neurological symptoms (FNS) are frequently encountered by neurologists and are difficult to treat. Symptoms are multiple and may appear concurrently or successively in the same patient. To date, few studies have been published on focal repetitive transcranial magnetic stimulation (rTMS) in FNS. This type of stimulation induces a focal current, vertically in the cortex. Results are contradictory, probably because it is difficult to identify a limited cortical area that triggers these symptoms. We assessed the efficacy of another type of rTMS: large-field stimulation by means of a circular coil covering a surface area approximately 20 times greater and inducing a circular current tangentially to the cortex.

PUBLISHED STUDIES

We analysed two studies on the efficacy of large-field rTMS in functional paralysis and in functional movement disorders. The efficacy of large-field rTMS was very marked in these two studies.

PERSONAL NON-PUBLISHED STUDIES

We reported several open series, including patients with functional sensory loss, functional visual loss, and non-epileptic seizures.

METHOD

For all patients, one or several sessions of 60 stimuli with circular coil were carried out with a protocol depending on the symptoms.

RESULTS

The efficacy of large-field rTMS was dramatic in all patient series. Additionally, we discuss the possible involved mechanism: placebo effect, cognitive behavioural effect or neuromodulatory effect.

CONCLUSION

According to the data from these different studies, large-field rTMS could be a new therapy for patients with FNS. However, controlled studies are mandatory.

The value of 'positive' clinical signs for weakness, sensory and gait disorders in conversion disorder: a systematic and narrative review

Experts in the field of conversion disorder have suggested for the upcoming DSM-V edition to put less weight on the associated psychological factors and to emphasise the role of clinical findings. Indeed, a critical step in reaching a diagnosis of conversion disorder is careful bedside neurological examination, aimed at excluding organic signs and identifying 'positive' signs suggestive of a functional disorder. These positive signs are well known to all trained neurologists but their validity is still not established. The aim of this study is to provide current evidence regarding their sensitivity and specificity. We conducted a systematic search on motor, sensory and gait functional signs in Embase, Medline, PsycINfo from 1965 to June 2012. Studies in English, German or French reporting objective data on more than 10 participants in a controlled design were included in a systematic review. Other relevant signs are discussed in a narrative review. Eleven controlled studies (out of 147 eligible articles) describing 14 signs (7 motor, 5 sensory, 2 gait) reported low sensitivity of 8-100% but high specificity of 92-100%. Studies were evidence class III, only two had a blinded design and none reported on inter-rater reliability of the signs. Clinical signs for functional neurological symptoms are numerous but only 14 have been validated; overall they have low sensitivity but high specificity and their use should thus be recommended, especially with the introduction of the new DSM-V criteria.

The elbow flex-ex: a new sign to detect unilateral upper extremity non-organic paresis

OBJECTIVE

To examine a new neurological sign that uses synergistic oppositional movements of the arms to evaluate for non-organic upper extremity weakness.

METHODS

Patients with unilateral arm weakness were tested in a standing or sitting position with the elbows flexed at 30°. The examiner held both forearms near the wrists while asking the patient to flex or extend the normal arm at the elbow and simultaneously feeling for flexion or extension of the contralateral (paretic) arm. In patients with organic paresis, there was not a significant detectable force of contralateral opposition of the paretic limb. Patients with non-organic arm weakness had detectable strength of contralateral opposition in the paretic arm when the normal arm was tested.

RESULTS

The test was first performed on 23 patients with no complaint of arm weakness. Then, 31 patients with unilateral arm weakness were tested (10 with non-organic weakness and 21 with organic weakness). The elbow flex-ex sign correctly identified the cause of weakness in all cases.

CONCLUSIONS

The elbow flex-ex sign is useful in differentiating between functional and organic arm paresis.

Misdiagnosis of stroke

Rapid diagnosis of stroke is necessary for the timely delivery of thrombolysis and evaluation of novel therapies such as neuroprotection. An accurate clinical history and competent examination are key to identifying which patients are likely to have had a stroke and arranging and interpreting neuroimaging. Stroke symptoms are typically acute in onset, but are highly variable depending on the vascular territory affected. Common presenting symptoms are limb weakness, and speech and visual disturbances. Common stroke mimics are seizures, space occupying lesions, syncope, somatization and delirium secondary to sepsis. Stroke recognition instruments can help nonspecialists in the early diagnosis of stroke, with studies reporting sensitivity of over 90% and specificity of approximately 85% for some instruments. In patients with a clinical diagnosis of stroke, brain computed tomography or MRI is required to exclude some stroke mimics and differentiate ischemic from hemorrhagic stroke, which is key to providing appropriate therapies such as thrombolysis. In the future, plasma biomarkers may improve clinical diagnosis of stroke, but prospective studies are required to establish their utility. Clinical trials of acute stroke therapies need to ensure rapid accurate diagnosis of stroke using structured clinical assessments and appropriate imaging to achieve early treatment and avoid entry of stroke mimics into trials.

Distinct modulation of event-related potentials during motor preparation in patients with motor conversion disorder

Objective

Conversion paresis patients and healthy people feigning weakness both exhibit weak voluntary movement without detectable neuropathology. Uniquely, conversion patients lack a sense of conscious awareness of the origin of their impairment. We investigated whether conversion paresis patients show distinct electroencephalographic (EEG) markers associated with their unconscious movement deficits.

Methods

Six unilateral upper limb conversion paresis patients, 12 feigning participants asked to mimic weakness and 12 control participants performed a precued reaction time task, requiring movements of either hand, depending on precue information. Performance measures (force, reaction and movement time), and event-related EEG potentials (ERP) were compared, between groups and across hands or hemisphere, using linear mixed models.

Results

Feigners generated the same inter-hand difference in reaction and movement time as expressed by patients, even though no specific targets were set nor feedback given on these measures. We found novel ERP signatures specific to patients. When the symptomatic hand was precued, the P3 ERP component accompanying the precue was dramatically larger in patients than in feigning participants. Additionally, in patients the earlier N1 ERP component was diminished when the precue signalled either the symptomatic or asymptomatic hand.

Conclusions

These results are consistent with previous suggestions that lack of awareness of the origin of their symptoms in conversion disorder patients may result from suppression of brain activity normally related to self-agency. In patients the diminished N1 to all precues is consistent with a generalised reduction in cognitive processing of movement-related precues. The P3 enhancement in patients is unlikely to simply reflect changes required for generation of impaired movements, because it was not seen in feigners showing the same behavioural deficits. Rather, this P3 enhancement in patients may represent a neural biomarker of unconscious processes, including additional emotional loading, related to active suppression of brain circuits involved in the attribution of self-agency.

[Somatoform disorders in neurology visits: history and circumstances: retrospective study of 124 cases]

We report 124 cases of somatoform disorders, considering psychogenic disorders at the same level as neurological disorders. We noted any psychic, somatic or social condition (history taking) and facilitating circumstances. The patients were aged 16 to 84 years old; 71.7% were women. We observed pain (35.4%), psychogenic headache (25%), sensorimotor loss (27.4%), gait and psychogenic tremor (17.7%), cognitive disorders (11.8%), ocular symptoms (7.2%), and urogenital symptoms (2.4%). Delay to consultation ranged from a few days to 20 years. Psychiatric comorbidity was noted in 30.6% of the cases. In 55.6% of 124 cases, we observed a psychological background. It was a childhood trauma in 15.3% of these cases. In one-third of the 124 situations, we noted an underlying somatic or social condition. Facilitation conditions were frequently mixed. Somatic and/or psychological conditions were noted in one-third of the 124 cases and social conditions in half of them. The neurologist is faced with the challenge of naming the symptom (most often labelled a functional disorder) and of making the decision to stop or limit investigations. Visits by patients with psychogenic disorders make up a significant percentage of neurology speciality appointments. The neurologist should not limit the consultation to differentiating "real" symptoms from psychogenic somatoform disorders, but should also propose a straightforward compassionate approach for effective therapeutic care. By carefully listening to the patient's dialogue, the neurologist can help the patient give meaning to the symptoms, and progress towards improved well-being.

Diagnosis and treatment of somatoform disorders

Many patients with somatoform disorders present to the neurology clinic, often after extensive evaluation that has left the patient and multiple other physicians frustrated. Knowledge of the typical characteristics of particular disorders enables the clinician to arrive at a positive diagnosis and facilitate referral to appropriate services. Using a series of representative cases, we review the DSM-IV-TR somatoform disorders most likely to present to the practicing neurologist, highlighting the epidemiologic features, typical presentations, and possible therapeutic approaches to each condition.

The symptom of functional weakness: a controlled study of 107 patients

Functional weakness describes weakness which is both internally inconsistent and incongruent with any recognizable neurological disease. It may be diagnosed as a manifestation of conversion disorder or dissociative motor disorder. Other names include psychogenic or 'non-organic' paralysis. We aimed to describe the incidence, demographic and clinical characteristics of cases with functional weakness of less than 2 years duration, and to compare these with controls with weakness attributable to neurological disease. Both cases and controls were recruited from consultant neurologists in South East Scotland. Participating patients underwent detailed assessments which included: physical examination, structured psychiatric interview (Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders), measures of symptoms, disability and distress [Short Form (36) Health Survey, Hospital and Anxiety Depression Scale], and assessment of their illness beliefs using an augmented version of the Illness Perception Questionnaire. In total, 107 cases (79% female, mean age 39 years, median duration of illness 9 months) were recruited. This number suggests a minimum annual incidence of 3.9/100 000. Forty-six controls (83% female, median age 39 years, duration 11 months) were also recruited. Compared to controls, cases had similar levels of disability but more physical symptoms, especially pain. They had a higher frequency of psychiatric disorders, especially current major depression (32 versus 7%, P < 0.0001), generalized anxiety disorder (21 versus 2%, P < 0.005), panic disorder (36 versus 13%, P < 0.001) and somatization disorder (27 versus 0%, P < 0001). There was no difference in median self-rated anxiety and depression scores. Paradoxically, they were less likely than controls to agree that stress was a possible cause of their illness (24 versus 56%, P < 0.001). Cases were twice as likely as controls to report that they were not working because of their symptoms (65 versus 33%, P < 0.0005). Functional weakness is a commonly encountered clinical problem. Patients with this symptom are as disabled as patients with weakness of similar duration due to neurological disease. There is a paradox between the frequency of depression and anxiety diagnoses and the patient's willingness to accept these as potentially relevant to their symptoms. We discuss the theoretical and practical implications of these findings for the concept of conversion disorder.

Psychogenic movement disorders

Psychogenic movement disorders (PMDs) represent a challenging dilemma for the treating neurologist. The terminology to classify this disorder is confusing and making the diagnosis is difficult. Once the diagnosis has been established, treatment options are limited, and the patient generally does not accept the diagnosis.

Abduction finger sign: a new sign to detect unilateral functional paralysis of the upper limb

Objective of this study is testing a new sign to differentiate functional from organic paralysis of the arm. Thirty-six healthy subjects, ten patients with acute functional paralysis of one arm and eleven patients with acute organic paralysis of one arm were enrolled. The test consisted of abduction finger movements of one hand against resistance with a maximal sustained contraction to detect synkinetic abduction finger movements of the contralateral hand. For both hands, contralateral hand synkinesias were observed in healthy subjects. The task performed with the unaffected hand evoked synkinesias of the presumed affected hand in functional patients, but did not evoke synkinesias of the affected hand in organic patients. The abduction finger test had 100% sensitivity and specificity in distinguishing functional from organic paralysis of the upper limb in this cohort of patients. The abduction finger sign may be a reliable bedside test to discriminate functional from organic arm paralysis.

Cauda equina syndrome with normal MR imaging

The aim of this study was to compare the clinical characteristics of patients with and without abnormal MR imaging admitted to a neurosurgical unit with suspected cauda equina syndrome using a retrospective study of consecutive admissions to a regional neurosurgical unit over a 10-month period. Clinical details were obtained from the case notes. A lumbar spine MR scan to investigate possible cauda equina syndrome was performed in 66 patients. There were no significant differences between those with abnormal imaging (n = 34, 52%) and those with a normal scan (n = 32, 48%) in respect of sex, clinical history or features recorded on examination. Those with normal imaging had a high frequency of weakness (n = 18, 59%), saddle numbness (n = 17, 57%), leg numbness (n = 24, 80%), urinary incontinence (n = 13, 54%) and urinary retention (n = 9, 53%). A large number of patients present to neurosurgical units with symptoms suggestive of cauda equina syndrome without any radiological evidence of structural pathology. While some may have had an alternative organic cause, we propose that these symptoms may have a "functional" origin in many patients.

Bedside assessment of stroke and stroke mimics

Following ischemic stroke, interventions to bring about reperfusion must be implemented within the recognized timeframe; this means that timely clinical recognition of this condition is vital. The process of diagnosis begins with the initial bedside assessment of the patient to be followed by appropriate imaging studies. However, because reperfusion therapy may be attended by significant adverse consequences, and since imaging may be negative for many hours after stroke onset, the clinician must be aware of conditions that mimic cerebral ischemia. Depending on the timing and nature of ancillary testing, stroke mimics can be identified in 3-30% of patients presenting with the acute onset of a neurological deficit. These mimics include metabolic, traumatic, migrainous, neoplastic, endocrine, convulsive, and psychiatric disorders. Interestingly, the nature of these mimics, their frequency of occurrence, and presentation may vary between different geographical regions; however, detailed information regarding such variations is not available at present. This review provides an overview of the conditions that can masquerade as stroke, and includes information that may aid in their early detection or, at the very least, serve to warn the clinician that the patient is presenting with something other than cerebral ischemia.

FMRI in patients with motor conversion symptoms and controls with simulated weakness

BACKGROUND

Conversion disorder (motor type) describes weakness that is not due to recognized disease or conscious simulation but instead is thought to be a "psychogenic" phenomenon. It is a common clinical problem in neurology but its neural correlates remain poorly understood.

OBJECTIVE

To compare the neural correlates of unilateral functional weakness in conversion disorder with those in healthy controls asked to simulate unilateral weakness.

METHODS

Functional magnetic resonance imaging (fMRI) was used to examine whole brain activations during ankle plantarflexion in four patients with unilateral ankle weakness due to conversion disorder and four healthy controls simulating unilateral weakness. Group data were analyzed separately for patients and controls.

RESULTS

Both patients and controls activated the motor cortex (paracentral lobule) contralateral to the "weak" limb less strongly and more diffusely than the motor cortex contralateral to the normally moving leg. Patients with conversion disorder activated a network of areas including the putamen and lingual gyri bilaterally, left inferior frontal gyrus, left insula, and deactivated right middle frontal and orbitofrontal cortices. Controls simulating weakness, but not cases, activated the contralateral supplementary motor area.

CONCLUSIONS

Unilateral weakness in established conversion disorder is associated with a distinctive pattern of activation, which overlaps with but is different from the activation pattern associated with simulated weakness. The overall pattern suggests more complex mental activity in patients with conversion disorder than in controls.

Long-term prognosis of patients with psychogenic movement disorders

Psychogenic movement disorders (PMD) are hyper- or hypokinetic movement disorders associated with underlying psychological or psychiatric disorders. Structured telephone interview was administered to 228 patients with PMD seen in our clinic between 1990 and 2003. The mean age of the subjects was 42.3+/-14.3 years (range 14-70 years), mean duration of symptoms was 4.7+/-8.1 years (range 2-14 years), and mean duration of follow-up was 3.4+/-2.8 years (6 months-12 years). Improvement of symptoms was noted in 56.6% patients; while 22.1% were worse, and 21.3% remained the same at the time of follow-up. In this longitudinal study of patients with PMD we found that indices of strong physical health, positive social life perceptions, patient's perception of effective treatment by the physician, elimination of stressors, and treatment with a specific medication contributed to a favorable outcome.

Functional Symptoms in Neurology: Case Studies

In this series of case vignettes, the authors have emphasized that the diagnosis of functional symptoms should normally rest on the presence of positive evidence of the problem being functional rather than the absence of evidence of organic disease. In addition, practitioners should be prepared to make a functional diagnosis in a patient who also has evidence of disease. Misdiagnosis of functional symptoms occurs no more than for other neuro-logical and psychiatric disorders. The neurologist has an important role in being able to transmit the diagnosis in a way that will not offend the patient but will also facilitate recovery. The key elements of this explanation are making the patient feel believed and emphasizing potential reversibility. A multidisciplinary approach involving concurrent physical and psychological treatments is often recommended, although further study is required to determine the best approaches to explain and treat these conditions.

Staying on the surface

Every neurologist needs to develop an effective technique to diagnose and manage non-organic disorders, although there are different ways to go about it. The complex relationship that exists between functional and organic illness is an inescapable theme in daily neurological practice. Usually, it is better to read these case stories by examining their surface detail rather than to try to understand their psychological depth.

La belle indifférence in conversion symptoms and hysteria: systematic review

BACKGROUND

La belle indifférence refers to an apparent lack of concern shown by some patients towards their symptoms. It is often regarded as typical of conversion symptoms/hysteria.

AIMS

To determine the frequency of la belle indifférence in studies of patients with conversion symptoms/hysteria and to determine whether it discriminates between conversion symptoms and symptoms attributable to organic disease.

METHOD

A systematic review of all studies published since 1965 that have reported rates of la belle indifférence in patients with conversion symptoms and/or patients with organic disease.

RESULTS

A total of 11 studies were eligible for inclusion. The median frequency of la belle indifférence was 21% (range 0-54%) in 356 patients with conversion symptoms, and 29% (range 0-60%) in 157 patients with organic disease.

CONCLUSIONS

The available evidence does not support the use of la belle indifférence to discriminate between conversion symptoms and symptoms of organic disease. The quality of the published studies is poor, with a lack off operational definitions and masked ratings. La belle indifférence should be abandoned as a clinical sign until both its definition and its utility have been clarified.

Psychogenic movement disorders

PURPOSE OF REVIEW

This review focuses on recent studies assessing clinical features and laboratory findings that may help diagnose psychogenic movement disorders, and the ongoing controversy about the relationship of these disorders with preceding peripheral injury.

RECENT FINDINGS

'Organic' movement disorders may still be misdiagnosed as psychogenic. Probably more commonly, however, psychogenic movement disorders are underdiagnosed. Most features typically associated with recognized movement disorders, including geste antagoniste or treatment-induced dyskinesias, can be seen in psychogenic movement disorder, and abnormal movements that would not normally be considered psychogenic or produced by psychological factors, such as palatal tremor, may occur on a psychogenic basis. On the other hand, psychiatric features are sometimes seen in neurologically based movement disorders. The diagnostic criteria for psychogenic movement disorders provide a degree of diagnostic certainty based on a combination of clinical and psychiatric features. Laboratory investigations can help exclude specific diagnoses, such as Parkinson's disease with (123I)beta-CIT single photon emission computed tomography, and neurophysiological methods can demonstrate characteristic features of psychogenic movement disorders, such as entrainment or suppression of psychogenic tremor with contralateral hand movements. However, some tests reported to differentiate psychogenic from neurological movement disorders may have incomplete specificity; for example, psychogenic tremor may not always be associated with complete coherence of tremor frequency. An ongoing controversy surrounds movement disorders following peripheral injuries, but recent evidence suggests that such patients should always be screened for the presence of a psychogenic movement disorder.

SUMMARY

Psychogenic movement disorder continues to be a difficult diagnosis to make and is likely to be underrecognized. Clinical and laboratory features are emerging, however, that support this diagnosis. The controversy regarding posttraumatic movement disorders continues, but a diagnosis of a psychogenic movement disorder should be actively sought in such patients.

Progress in understanding conversion disorder

Conversion disorder has a history that may reach back into antiquity, and it continues to present a clinical challenge to both psychiatrists and neurologists. This article reviews the current state of knowledge surrounding the prevalence, etiology, and neurobiology of conversion disorder. There have been improvements in the accuracy of diagnosis that are possibly related to improved technologies such as neuroimaging. Once the diagnosis is made, it is important to develop a therapeutic alliance between the patient and the medical team, and where comorbid psychiatric diagnoses have been made, these need to be adequately treated. While there have been no formal trials of medication or psychoanalytic treatments in this disorder, case reports suggest that a combination of antidepressants, psychotherapy, and a multidisciplinary approach to rehabilitation may be beneficial.

Functional symptoms in neurology: questions and answers

Between 10 and 30% of patients seen by neurologists have symptoms for which there is no current pathophysiological explanation. The objective of this review is to answer questions many neurologists have about disorders characterised by unexplained symptoms (functional disorders) by conducting a multidisciplinary review based on published reports and clinical experience. Current concepts explain functional symptoms as resulting from auto-suggestion, innate coping styles, disorders of volition or attention. Predisposing, precipitating, and perpetuating aetiological factors can be identified and contribute to a therapeutic formulation. The sympathetic communication of the diagnosis by the neurologist is important and all patients should be screened for psychiatric or psychological symptoms because up to two thirds have symptomatic psychiatric comorbidity. Treatment programmes are likely to be most successful if there is close collaboration between neurologists, (liaison) psychiatrists, psychologists, and general practitioners. Long term, symptoms persist in over 50% of patients and many patients remain dependent on financial help from the government. Neurologists can acquire the skills needed to engage patients in psychological treatment but would benefit from closer working relationships with liaison psychiatry or psychology.

Clinical features associated with medically unexplained stroke-like symptoms presenting to an acute stroke unit

In many areas of secondary care, symptoms unexplained by disease account for around one-third of all patients seen. We sought to investigate patients presenting with medically unexplained stroke-like symptoms to identify distinguishing features which may help to identify a non-organic aetiology. Patients given a discharge diagnosis of medically unexplained stroke-like symptoms over the preceding 11 years were identified retrospectively from a prospectively completed stroke unit database. Age- and sex-matched controls with ischaemic or haemorrhagic stroke or transient ischaemic attack were also identified. Clinical features on presentation, ischaemic risk factors, alcohol history, marital status and history of depression or anxiety were examined. Previous or subsequent admissions with medically unexplained syndromes were also examined via record linkage with hospital discharge records. A medically unexplained syndrome was assumed to be present if an International Classification of Diseases 9 discharge code for one or more of the thirteen conditions forming recognized functional syndromes was given. Logistic regression was applied to determine predictors of non-organicity. One hundred and five patients and controls, 1.6% of all stroke unit admissions were identified, 62% (65 patients) were females. Mean age was 50.3 +/- 14.9. Compared with age- and sex-matched controls patients with medically unexplained stroke-like symptoms were significantly more probable to have a headache at presentation (47% vs. 26%, P = 0.0004), have a diagnosis of one or more additional medically unexplained syndromes (24% vs. 11%, P = 0.007) but significantly less probable to present with symptoms of vertebrobasilar dysfunction (32% vs. 61%, P < 0.0001). A history of anxiety or depression, as recorded in the notes, was not found to be associated with a medically unexplained presentation. Medically unexplained stroke-like presentations are common (1.6% of all stroke presentations), they are most strongly predicted by the presence of other functional somatic syndromes, headache and the absence of symptoms of vertebrobasilar dysfunction.

Psychogenic movement disorders: diagnosis and management

Psychogenic movement disorders (PMDs) are best defined as hyper- or hypo-kinetic movement disorders, often associated with gait disorders, that cannot be directly attributed to a lesion or dysfunction of the nervous system and which are derived in most cases from psychological or psychiatric causes. There are a variety of PMDs including tremor, dystonia, parkinsonism, gait disorders and, even, unusual forms including paroxysmal dyskinesias. As has been recognised in the recent literature, PMDs cannot be strictly classified into clearly defined psychiatric disorders such as somatoform, dissociative or conversion disorders. In this review, we discuss the diagnosis of various PMDs (including hyper- and hypo-kinetic disorders; and current evidence for underlying comorbid disorders) and the current therapeutic approach to them. The therapy of PMDs is not well established, is very challenging to the clinician, and a better outcome can be achieved in the setting of a team approach involving movement disorders specialists, psychiatrists and therapists who specialise in cognitive-behavioural techniques. Current pharmacological and non-pharmacological approaches to treatment focus on therapy of underlying comorbid psychiatric and psychological issues, although compliance is a major concern.

Hemisensory syndrome is associated with a low diagnostic yield and a nearly uniform benign prognosis

OBJECTIVE

To describe the diagnostic yield and prognosis for patients with hemisensory syndrome.

BACKGROUND

The aetiology, utility of diagnostic procedures, and outcome of hemisensory syndrome in patients with exclusive hemibody complaints having only subjective sensory abnormalities on examination is unknown.

METHODS

Patients were prospectively identified with hemisensory syndrome in a tertiary care institution from 1998-2002. Diagnostic procedures were analysed for sensitivity and clinical follow up was performed.

RESULTS

Thirty four patients, 25 (74%) women, of age 35 (SD 11) years were identified. The hemisensory syndrome occurred on the left side in 23 (68%) cases. Neuroimaging of the brain demonstrated diagnostic abnormalities representing ischaemic aetiology in one case. Other diagnostic testing including cerebrospinal fluid examination, electrophysiological testing, carotid ultrasonography, echocardiography, and blood testing revealed no diagnostic abnormalities. Sixteen patients (47%) continued to complain of hemisensory difficulties after all investigations were completed at 9.6 (5.8) days. One patient with a history of systemic lupus erythematosus and positive antiphospholipid antibodies had a second event diagnosed as stroke seven months after presentation. Clinical follow up at 16 (7) months revealed persisting symptoms in 6 (20%) of 30 patients. Six (50%) of 12 patients agreeing to psychiatric assessment received diagnoses of personality or mood disorders.

CONCLUSIONS

Diagnostic yield in hemisensory syndrome is low, and prognosis is almost always uniformly benign. The author advocates careful assessment of medical history and consideration for neuroimaging in this group of patients.

The 12 year prognosis of unilateral functional weakness and sensory disturbance

BACKGROUND

Although the symptoms of unilateral "medically unexplained" or "functional" weakness and sensory disturbance present commonly to neurologists, little is known about their long term prognosis.

OBJECTIVE

To determine the long term outcome of functional weakness and sensory disturbance.

PATIENTS

A previously assembled cohort of 60 patients seen as inpatients by consultant neurologists in Edinburgh between 1985 and 1992 and diagnosed as having unilateral functional weakness or sensory disturbance.

METHODS

Current symptoms, disability, and distress were assessed by postal questionnaire to the patients and their family doctors.

RESULTS

Follow up data relating to mortality were obtained in 56 patients (93%) and to current diagnosis in 48 patients (80%). Patient questionnaire data were obtained in 42 patients (70%). The median duration of follow up was 12.5 years (range 9 to 16). Thirty five of the 42 patients (83%) still reported weakness or sensory symptoms, and the majority reported limitation of physical function, distress, and multiple other somatic symptoms. Twenty nine per cent had taken medical retirement. An examination of baseline predictors indicated that patients who had sensory symptoms had better functioning at follow up than those who had weakness. Only one patient had developed a neurological disorder which, in hindsight, explained the original presentation. Another patient had died of unrelated causes.

CONCLUSIONS

Many patients assessed by neurologists with unilateral functional weakness and sensory symptoms as inpatients remain symptomatic, distressed, and disabled as long as 12 years after the original diagnosis. These symptoms are only rarely explained by the subsequent development of a recognisable neurological disorder in the long term.