Somatoform Disorders After Temporal Lobectomy

The pathophysiology of functional movement disorders

Functional neurological disorder is characterized by neurological symptoms that cannot be explained by typical neurological diseases or other medical conditions. This review will critically discuss the literature on the pathophysiology of functional movement disorders (FMD), including functional neuroimaging studies, neurophysiological studies, studies on biomarkers and genetic studies. According to PRISMA guidelines for systematic reviews, we selected 39 studies. A complex scenario emerged, with the involvement of different areas of the brain in the pathophysiology of FMD. Our findings showed a hypoactivation of the contralateral primary motor cortex, a decreased activity in the parietal lobe, an aberrant activation of the amygdala, an increased temporo-parietal junction activity and a hyperactivation of insular regions in patients with FMD. Functional connectivity (FC) findings underlined aberrant connections between amygdala and motor areas, temporo-parietal junction and insula. We proposed amygdala hyperactivation as a possible biological marker for FMD and FC alterations between amygdala and other areas of the brain as consequent epiphenomena, accounting for the pathophysiological complexity of FMD. These conclusions might drive novel treatment hypotheses.

Does antiepileptic drug withdrawal predispose patients undergoing temporal lobe epilepsy surgery to late onset of psychiatric morbidity? A report of three cases

Surgery is an established and increasingly utilized treatment option in medically refractory temporal lobe epilepsy. Many psychiatric problems are known to complicate in the postoperative period. Most studies have a follow-up period of less than 24 months. We report the cases of three patients who developed severe psychiatric problems in the late postoperative period after successful temporal lobectomy for refractory epilepsy — Psychosis, major depression with psychosis, and severe anxiety disorder, respectively. None of the patients had past or family history of psychiatric disease. All three patients had undergone anterior temporal lobectomy on the right side for intractable epilepsy. They remained absolutely seizure-free after surgery. We conclude that psychiatric morbidity may arise de novo long after temporal lobectomy. This association between temporal lobectomy for epilepsy and late onset psychiatric morbidity should be carefully studied. Mechanisms underlying this late complication require deeper understanding of the effects of epilepsy surgery.

Neural correlates of conversion disorder: overview and meta-analysis of neuroimaging studies on motor conversion disorder

BACKGROUND

Conversion Disorders (CD) are prevalent functional disorders. Although the pathogenesis is still not completely understood, an interaction of genetic, neurobiological, and psychosocial factors is quite likely. The aim of this study is to provide a systematic overview on imaging studies on CDs and investigate neuronal areas involved in Motor Conversion Disorders (MCD).

METHODS

A systematic literature search was conducted on CD. Subsequently a meta-analysis of functional neuroimaging studies on MCD was implemented using an Activation Likelihood Estimation (ALE). We calculated differences between patients and healthy controls as well as between affected versus unaffected sides in addition to an overall analysis in order to identify neuronal areas related to MCD.

RESULTS

Patients with MCD differ from healthy controls in the amygdala, superior temporal lobe, retrosplenial area, primary motor cortex, insula, red nucleus, thalamus, anterior as well as dorsolateral prefrontal and frontal cortex. When comparing affected versus unaffected sides, temporal cortex, dorsal anterior cingulate cortex, supramarginal gyrus, dorsal temporal lobe, anterior insula, primary somatosensory cortex, superior frontal gyrus and anterior prefrontal as well as frontal cortex show significant differences.

CONCLUSIONS

Neuronal areas seem to be involved in the pathogenesis, maintenance or as a result of MCD. Areas that are important for motor-planning, motor-selection or autonomic response seem to be especially relevant. Our results support the emotional unawareness theory but also underline the need of more support by conduction imaging studies on both CD and MCD.

Pain and temperature processing in dementia: a clinical and neuroanatomical analysis

Symptoms suggesting altered pain and temperature processing have been described in dementia diseases. Using a semi-structured caregiver questionnaire and MRI voxel-based morphometry in patients with frontotemporal degeneration or Alzheimer’s disease, Fletcher et al. show that these symptoms are underpinned by atrophy in a distributed thalamo-temporo-insular network implicated in somatosensory processing.

Symptoms suggesting altered processing of pain and temperature have been described in dementia diseases and may contribute importantly to clinical phenotypes, particularly in the frontotemporal lobar degeneration spectrum, but the basis for these symptoms has not been characterized in detail. Here we analysed pain and temperature symptoms using a semi-structured caregiver questionnaire recording altered behavioural responsiveness to pain or temperature for a cohort of patients with frontotemporal lobar degeneration (n = 58, 25 female, aged 52–84 years, representing the major clinical syndromes and representative pathogenic mutations in the C9orf72 and MAPT genes) and a comparison cohort of patients with amnestic Alzheimer’s disease (n = 20, eight female, aged 53–74 years). Neuroanatomical associations were assessed using blinded visual rating and voxel-based morphometry of patients’ brain magnetic resonance images. Certain syndromic signatures were identified: pain and temperature symptoms were particularly prevalent in behavioural variant frontotemporal dementia (71% of cases) and semantic dementia (65% of cases) and in association with C9orf72 mutations (6/6 cases), but also developed in Alzheimer’s disease (45% of cases) and progressive non-fluent aphasia (25% of cases). While altered temperature responsiveness was more common than altered pain responsiveness across syndromes, blunted responsiveness to pain and temperature was particularly associated with behavioural variant frontotemporal dementia (40% of symptomatic cases) and heightened responsiveness with semantic dementia (73% of symptomatic cases) and Alzheimer’s disease (78% of symptomatic cases). In the voxel-based morphometry analysis of the frontotemporal lobar degeneration cohort, pain and temperature symptoms were associated with grey matter loss in a right-lateralized network including insula (P < 0.05 corrected for multiple voxel-wise comparisons within the prespecified anatomical region of interest) and anterior temporal cortex (P < 0.001 uncorrected over whole brain) previously implicated in processing homeostatic signals. Pain and temperature symptoms accompanying C9orf72 mutations were specifically associated with posterior thalamic atrophy (P < 0.05 corrected for multiple voxel-wise comparisons within the prespecified anatomical region of interest). Together the findings suggest candidate cognitive and neuroanatomical bases for these salient but under-appreciated phenotypic features of the dementias, with wider implications for the homeostatic pathophysiology and clinical management of neurodegenerative diseases.

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.

Quantification of a secondary task-specific tremor in a violinist after a temporal lobectomy

Task-specific tremors (TSTs) occur mainly during certain tasks and may be highly disabling. In this case study, we report on a 66-year-old violinist who developed a TST of the right arm only while playing the violin 4 weeks after a temporal lobectomy, which had been performed as a result of his temporal lobe epilepsy. Since a similar case, to our knowledge, has not been reported so far, our aim was to quantitatively assess and describe the tremor by measuring (a) the electromyography (EMG) activity of the wrist flexor and extensor as well as (b) an accelerometer signal of the hand. We found a tremor-related frequency of about 7 Hz. Furthermore, at a similar frequency of about 7 Hz, there was coherence between the tremor acceleration and EMG-activity of the wrist flexor and extensor as well as between the tremor acceleration and coactivation. The tremorgenesis remains unclear, and possible explanations can only be speculative.

Astasia-abasia and psychogenic tremor post-temporal lobectomy

Temporal lobectomy can be complicated by somatoform disorders, psychiatric illnesses and non-epileptic psychogenic seizures. We report a woman who developed astasia-abasia and psychogenic tremor following temporal lobectomy for refractory epilepsy. To our knowledge, this type of conversion reaction following temporal lobectomy has not been previously reported.

The pathophysiology of body dysmorphic disorder

Body dysmorphic disorder (BDD) is an often severe and disabling condition, affecting up to 2% of the population. Despite its prevalence and clinical significance, very little is known about the pathophysiology of BDD. However, clues to its possible neurobiological substrates and abnormalities in information processing are starting to emerge. This article reviews findings from genetic, brain lesion, neuroimaging, neuropsychological, and psychopharmacological studies that have allowed us to develop a tentative model of the functional neuroanatomy of BDD. There is likely a complex interplay of dysfunctions in several brain networks underlying the pathophysiology of BDD. A combination of dysfunctions in frontal-subcortical circuits, temporal, parietal, and limbic structures, and possibly involving hemispheric imbalances in information processing, may produce both the characteristic symptoms and neurocognitive deficits seen in BDD. An improved understanding of the pathophysiology of BDD will be crucial to guide the development of better treatments.

Psychiatric outcome of surgery for temporal lobe epilepsy and presurgical considerations

In recent years, surgery has become a treatment option for some patients with intractable epilepsy, particularly those with temporal lobe epilepsy. Psychiatric disturbances may complicate the postsurgical outcome in some patients and de novo psychiatric symptoms have been reported. In many but not all epilepsy surgical centres, a psychiatric assessment is included as part of the presurgical evaluation of potential candidates for surgery. This review indicates that affective disorders, namely, depression and anxiety, and psychosis are the most frequently reported postsurgical psychiatric disturbances. Whilst there are no absolute psychiatric contraindications to surgery, certain pre-existing psychiatric conditions may need careful consideration as there may be a risk of postsurgical psychiatric complications. Routine pre- and postsurgical psychiatric evaluations in patients undergoing epilepsy surgery are recommended. Clinicians involved in the care of surgical candidates should be aware of the possible psychiatric complications following surgery and ensure that the psychiatric risks are discussed with the patient and family.

Somatoform disorders in neurological practice

PURPOSE OF REVIEW

Patients with medically unexplained symptoms continue to intrigue, fascinate and frustrate clinicians. They are common in general medicine and often present with apparent neurological disorder. This review aims to provide insight into the recent literature that has sought to clarify epidemiology, diagnostic issues, aetiologic understanding and treatment of patients with psychogenic disorders who usually first present to neurologists.

RECENT FINDINGS

Somatoform disorders are common in neurological practice. A number of papers have addressed issues of epidemiology and identified that medically unexplained symptoms in neurological populations are higher than originally thought. A number of recent review papers have served to summarize areas of considerable information (e.g. treatments) and areas of rapid growth in knowledge (e.g. neuroimaging). Studies investigating the role of psychological factors are well represented and clarify our psychopathological understanding of somatoform disorders in patients presenting to neurologists. Treatment studies are few and continue to be limited by population sizes and study designs.

SUMMARY

Somatoform disorders are common in neurological populations. Comorbidity related to somatoform disorders with known organic neurological conditions requires further study. On account of the limitations of treatment studies, evidence-based clinical management of these patients is awaited.

Body Dysmorphic Disorder

Body dysmorphic disorder is a relatively common psychiatric disorder among the dermatology patient population. These individuals may present to dermatologists for treatment of normal or minimally abnormal skin findings. Recognizing that these patients have body dysmorphic disorder can avert unnecessary and potentially unsuccessful treatments. Understanding and directing patients toward appropriate treatment options can minimize the distress and morbidities associated with the disorder.

Social cognition and epilepsy surgery

Human social behavior depends on a set of perceptive, mnemonic, and interpretive abilities that together may be termed social cognition. Lesion and functional imaging studies of social cognitive functions implicate the temporal lobes (in particular, the nondominant temporal lobe) and mesial temporal structures as critical at the front end of social cognitive processes. The frontal lobes, in turn, function to interpret and to modulate these processes via top-down control. Damage to frontal regions is associated with specific derangements in social behavior. Chronic focal-onset epilepsy and its surgical treatment commonly affect these neuroanatomic regions and might therefore impact social function. Postoperative social function helps determine quality of life for both patients and families. There is some evidence that resective seizure surgery affects social cognition, but there are significant weaknesses in our current knowledge that can be overcome with comprehensive longitudinal research.