Posttraumatic movement disorders: a review

Disorders of Movement due to Acquired and Traumatic Brain Injury

Purpose of Review

Both traumatic and acquired brain injury can result in diffuse multifocal injury affecting both the pyramidal and extrapyramidal tracts. Thus, these patients may exhibit signs of both upper motor neuron syndrome and movement disorder simultaneously which can further complicate diagnosis and management. We will be discussing movement disorders following acquired and traumatic brain injury.

Recent Findings

Multiple functions including speech, swallowing, posture, mobility, and activities of daily living can all be affected. Medical treatment and rehabilitation-based therapy can be especially challenging due to accompanying cognitive deficits and severity of the disorder which can involve multiple limbs in addition to muscles of the face and axial skeleton. Tremor and dystonia are the most reported movement disorders following traumatic brain injury. Dystonia and myoclonus are well documented following hypoxic ischemic brain injuries. Electrophysiological studies such as dynamic surface poly-electromyography can assist with identifying phenomenology, especially differentiating between jerk-like phenomenon and help guide further work up and management. Management with medications remains challenging due to potential adverse effects. Surgical interventions including stereotactic surgery, deep brain stimulation, and intrathecal baclofen pumps have been reported, but most of the evidence supporting them has been limited to primarily case reports except for post-traumatic tremor.

Summary

Brain injury can lead to motor disorders, movement disorders, visual (processing) deficits, and vestibular deficits which often coexist with cognitive deficits making it challenging to treat and rehabilitate these patients. Unfortunately, the evidence regarding the medical management and rehabilitation of brain injury patients with movement disorders is sparse and leaves much to be desired.

A Review of Tics Presenting Subsequent to Traumatic Brain Injury

Purpose of review

This review summarizes case reports of patients with tics emerging subsequent to traumatic brain injury (TBI), with respect to demographics, post-TBI symptoms, tic onset latency and topography, clinical history, neuroimaging results and treatment outcome.

Recent findings

Patients were 22 adults and 3 youth. Trauma onset appeared to fall mostly in adulthood. Two-thirds of patients were male and head trauma was related to motor vehicle accidents in most cases. Loss of consciousness was reported in just below half (48.0%) of cases. Associated physical and cognitive symptoms (e.g., impaired memory, reduced sensory perception, poor balance, muscle weakness, attention problems, aggression/impulsivity, obsessions and compulsions, depression and anxiety) were commonly reported. The latency between head trauma and tic onset varied, but generally ranged from one day post-trauma to approximately one year post-trauma. Sole presentation of motor tics was common, with rostral to caudal development of motor tics in other cases. Simple and/or complex vocal tics were present in several cases, often emerging after motor tics. Post-trauma obsessive-compulsive symptoms were noted in five cases (20.0%). A personal or family history of tics was reported in four cases. Damage to the basal ganglia, ventricular system, and temporal region was observed across ten patients (40.0%). Pharmacological intervention varied, with tic symptoms deemed to have significantly or somewhat improved in 12 cases (48.0%). A comparison of post-TBI symptoms in youth with head trauma history relative to those with peripheral injury suggests tic symptoms are not a common post-TBI symptom in youth.

Summary

Ultimately, there has been limited study on the link between traumatic brain injury and tic expression, and methodological issues preclude the ability to draw definitive conclusions regarding this relationship. Nevertheless, findings do suggest there may be heterogeneity in brain dysfunction associated with tic expression. Future case reports should utilize more systematic and thorough assessment of TBI and tics using validated measures, evaluate medication effects using single-case designs, and perform more longitudinal follow-up of cases with repeated neuroimaging.

Possible Post-Traumatic Focal Dystonia Associated with Tau Pathology Localized to Putamen-Globus Pallidus

Background

Dystonia is often associated with damage to basal ganglia (BG), but neuropathological assessments of these cases are infrequent.

Methods

A brain was assessed with possible post-traumatic focal dystonia that appeared after an accident occurred during childhood.

Results

Tau pathology was found within putamen and globus pallidus of the right hemisphere, and chronic traumatic encephalopathy (CTE) was observed in the cortex of the left hemisphere. No diffuse axonal injury (DAI), β-amyloid, ubiquitin, p62, or pTDP43 pathology was found.

Conclusions

Post-traumatic dystonia could be associated with post-traumatic tau pathology formation. However, more cases are necessary to establish causality. The tau lesions found in the BG of this patient did not fit within CTE criteria. We hypothesize that due to the anatomo-histological characteristics of the BG, tau pathology associated with brain traumas produce histopathological patterns different from sulcal-tau pathology, which is the only tau pathology distribution currently accepted as pathognomonic of CTE.

Symptomatic Dystonia: Clinical Profile of 46 Brazilian Patients

Dystonia is a syndrome characterized by sustained muscle contraction, provoking twisting and repeti-tive movements or abnormal postures. It may be classified according to etiology, as idiopathic or symptomatic. We studied 122 Brazilian patients with a dystonic syndrome. Of these, 46 (37.7%) had symptomatic dystonia. The most frequent cause was tardive dystonia (34.8%) followed by perinatal cerebral injury (30.4%). Other causes were stroke (13.0%), encephalitis (6.5%) and Wilson’s disease (4.3%). Cranial trauma, mitochondrial cytopathy and psychogenic, were the least frequent causes with one patient in each category. The etiology in two patients could not be established. Perinatal cerebral injury and postencephalitic dystonia were seen in the younger age group, while post-stroke and tardive dystonia were seen in the older age group.

Movement disorders secondary to craniocerebral trauma

Over the past few decades it has been recognized that traumatic brain injury may result in various movement disorders. In survivors of severe head injury, post-traumatic movement disorders were reported in about 20%, and they persisted in about 10% of patients. The most frequent persisting movement disorder in this population is kinetic cerebellar outflow tremor in about 9%, followed by dystonia in about 4%. While tremor is associated most frequently with cerebellar or mesencephalic lesions, patients with dystonia frequently have basal ganglia or thalamic lesions. Moderate or mild traumatic brain injury only rarely causes persistent post-traumatic movement disorders. It appears that the frequency of post-traumatic movement disorders overall has been declining which most likely is secondary to improved treatment of brain injury. In patients with disabling post-traumatic movement disorders which are refractory to medical treatment, stereotactic neurosurgery can provide long-lasting benefit. While in the past the primary option for severe kinetic tremor was thalamotomy and for dystonia thalamotomy or pallidotomy, today deep brain stimulation has become the preferred treatment. Parkinsonism is a rare consequence of single head injury, but repeated head injury such as seen in boxing can result in chronic encephalopathy with parkinsonian features. While there is still controversy whether or not head injury is a risk factor for the development of Parkinson's disease, recent studies indicate that genetic susceptibility might be relevant.

Advances in neuropharmacological rehabilitation for brain dysfunction

The use of pharmacological agents as rehabilitative tools following brain injury remains to some degree both a science and an art. Recent work in the area of the neural sciences has shed new light on the workings of basic CNS neurochemical systems and the use of pharmacologic agents in altering central neurophysiologic processes. The major central neurochemical systems are reviewed both anatomically and physiologically. An overview is provided of basic neuropharmacologic agents by class. Lastly, some of the newer neuropharmacological options for treatment of post-acute brain injury deficits are examined.

Thalamic deep brain stimulation for posttraumatic action tremor

We report a case of thalamic deep brain stimulation (DBS) for treatment of posttraumatic tremor. An 18-year-old right-handed man developed a disabling and medically refractory action tremor in the right upper extremity 9 months after sustaining diffuse axonal injury in a motor vehicle collision. DBS of the left ventral intermediate nucleus of the thalamus (Vim) suppressed the tremor without complication and should be considered as an option for the management of intractable posttraumatic tremor.

Head injury and posttraumatic movement disorders

WE REVIEW THE phenomenology, pathophysiology, pathological anatomy, and therapy of posttraumatic movement disorders with special emphasis on neurosurgical treatment options. We also explore possible links between craniocerebral trauma and parkinsonism. The cause-effect relationship between head injury and subsequent movement disorder is not fully appreciated. This may be related partially to the delayed appearance of the movement disorder. Movement disorders after severe head injury have been reported in 13 to 66% of patients. Although movement disorders after mild or moderate head injury are frequently transient and, in general, do not result in additional disability, kinetic tremors and dystonia may be a source of marked disability in survivors of severe head injury. Functional stereotactic surgery provides long-term symptomatic and functional benefits in the majority of patients. Thalamic radiofrequency lesioning, although beneficial in some patients, frequently is associated with side effects such as increased dysarthria or gait disturbance, particularly in patients with kinetic tremor secondary to diffuse axonal injury. Deep brain stimulation is used increasingly as an option in such patients. It remains unclear whether pallidal or thalamic targets are more beneficial for treatment of posttraumatic dystonia. Trauma to the central nervous system is an important causative factor in a variety of movement disorders. The mediation of the effects of trauma and the pathophysiology of the development of posttraumatic movement disorders require further study. Functional stereotactic surgery should be considered in patients with disabling movement disorders refractory to medical treatment.

Intrafamilial phenotypic variability of the DYT1 dystonia: from asymptomatic TOR1A gene carrier status to dystonic storm

When primary torsion dystonia is caused by a GAG deletion in the TOR1A gene (DYT1 dystonia), it typically presents with an early-onset dystonia involving distal limbs, subsequently spreading to a generalized dystonia. We describe a large family with an unusually broad variability in the clinical features of their dystonia both with regard to severity and age of onset. The proband of this family succumbed in his second decade to malignant generalized dystonia, whereas other family members carrying the same mutation are either asymptomatic or display dystonia that may be focal, segmental, multifocal, or generalized in distribution. One family member had onset of her dystonia at age 64 years, probably the oldest reported in genetically confirmed DYT1 dystonia. We conclude that marked phenotypic heterogeneity characterizes some families with DYT1 dystonia, suggesting a role for genetic, environmental, or other modifiers. These findings have implications for genetic testing and counseling.

Holmes' tremor following midbrain Toxoplasma abscess: clinical features and treatment of a case

The label Holmes' tremor defines a rare symptomatic movement disorder frequently occurring with midbrain damage. It appears at rest and worsens adopting a posture and on attempting movements. We describe the case of a patient with Holmes' tremor due to a presumed Toxoplasma abscess of the midbrain. The positive response to a combined therapy with levodopa and isoniazid is also reported.

The effects of proprioceptive stimulation on cognitive processes in patients after traumatic brain injury

OBJECTIVE

To investigate the hypothesis that proprioceptive stimulation may be effective in the treatment of brain injury, using neurophysiologic and neuropsychologic measures.

DESIGN

Cohort analytic study.

SETTING

Patients recovering from traumatic brain injury (TBI) in a neurologic rehabilitation hospital were examined.

PARTICIPANTS

Eleven patients with TBI (Glasgow Coma Scale score > 3) and 11 healthy control subjects matched for age and education.

INTERVENTIONS

Subjects were examined with the event-related potential (ERP) technique during a computerized choice-reaction-time task, in which they had to discriminate between even and odd digits. There were experimental runs with and without vibratory stimuli applied to the left forearm serving as proprioceptive stimulation. In addition, ERPs were recorded to vibratory stimuli without any additional task.

MAIN OUTCOME MEASURES

Outcome measures included latencies and amplitudes of the P300 ERP component and of the late negative component.

RESULTS

In the passive vibration condition, both groups showed the same ERP distribution. In the choice-reaction-time task, latencies and amplitudes of the P300 differed between the 2 groups. The patient group showed longer P300 latencies, which were shortened by vibratory stimuli. In contrast, the control subjects were not affected by vibratory stimuli.

CONCLUSION

Our findings support the hypothesis that pathologic cognitive processes after TBI can be improved by proprioceptive stimulation. Muscle vibration has positive effects on pathologically slowed cognitive processes but not in healthy subjects.

Other Parkinson syndromes

The etiology of parkinsonism is varied. Symptomatic parkinsonism is seen in the setting of genetic disorders, infectious processes, structural lesions, and as a result of concomitant medications. A thorough history and good examination will differentiate PD from the diverse group of conditions that can mimic it.

[Myoclonus in the adult: diagnostic approach]

Myoclonus, defined as shock-like involuntary movement, may be physiological or caused by a very wide variety of hereditary and acquired conditions. Because myoclonus can originate from different disorders and lesions affecting quite varied levels of the central and peripheral nervous systems, it represents from many points of view a diagnostic challenge. Moreover, new entities have been recently individualized, such as cortical tremor, which deserve renewed attention. The aim of this review is to propose a rationale for a diagnostic approach based on clinical and electrophysiological grounds. In this setting, we successively address 1) the clinical features allowing a positive diagnosis of myoclonus; 2) the clinical clues to the etiology; 3) the relevance of the clinical context to the diagnosis; and 4) the contribution of neurophysiology. Differentiating myoclonus from tics, spasm, chorea and dystonia can be difficult, and a careful reappraisal of clinical features allowing precise identification is presented. Moreover, the topographical distribution of myoclonus, the temporal pattern of muscle recruitment, the condition of occurrence and the rhythm of the event, may provide clinical clues relevant to the diagnosis. Myoclonus without associated epilepsy, myoclonus with epilepsy, myoclonus with encephalopathy, parkinsonism and/or dementia represent overlapping clinical categories, although they remain useful for the diagnostic approach. Using electrophysiology (including back-averaging EEG, MEG, SEP, C-reflex studies) to determine the origin of myoclonus may not allow us to focus on the underlying condition. Indeed, in many instances, the myoclonus is cortical in origin, but the pathology is found elsewhere.

Posttraumatic akinetic-rigid syndrome resembling Parkinson's disease: a report on three patients

We describe three patients who developed a rapidly evolving posttraumatic akinetic-rigid syndrome (ARS), the clinical manifestations of which were similar to Parkinson's disease, including response to levodopa. Despite initial imaging studies showing traumatic damage to the substantia nigra, the ARS appeared after a delay of 1-5 months after the injury. We stress the importance of magnetic resonance imaging to illustrate nigral damage in all patients in whom head trauma precedes an ARS.

Long-term follow-up study of chronic globus pallidus internus stimulation for posttraumatic hemidystonia

The authors report the first case of chronic globus pallidus internus (GPi) stimulation for treatment of medically intractable hemidystonia for which long-term follow-up data are available. The patient had developed left-sided low-frequency tremor and hemidystonia after a severe head trauma sustained at 15 years of age. He experienced relief of the tremor but not of the hemidystonia after a thalamotomy was performed in the right hemisphere 3 years postinjury. When the patient was 24 years old, the authors performed a magnetic resonance-guided stereotactic implantation of a monopolar electrode in the right-sided posteroventral GPi. Chronic deep brain stimulation resulted in remarkable improvement of dystonia-associated pain, phasic dystonic movements, and dystonic posture, which was accompanied by functional gain. Postoperative improvement was sustained after 4 years of follow up. Chronic GPi stimulation appears to be a valuable treatment option for posttraumatic dystonia.

Post-traumatic cervical dystonia: a distinct entity?

BACKGROUND/OBJECTIVE

The incidence of head/neck trauma preceding cervical dystonia (CD) has been reported to be 5-21%. There are few reports comparing the clinical characteristics of patients with and without a history of injury. Our aim was to compare the clinical characteristics of idiopathic CD (CD-I) to those with onset precipitated by trauma (CD-T).

METHODS

We evaluated 114 consecutive patients with CD over a 9-month period. All patients were interviewed using a detailed questionnaire and had a neurological examination. Their clinical charts were also reviewed.

RESULTS

Fourteen patients (12%) had mild head/neck injury within a year preceding the onset of CD. Between the two groups (CD-I and CD-T), the gender distribution (F:M of 3:2), family history of movement disorders (32% vs. 29%), the prevalence of gestes antagonistes (65% vs. 64%), and response to botulinum toxin were similar. There were non-specific trends, including an earlier age of onset (mean ages 43.3 vs. 37.6), higher prevalence of neck pain (86% vs. 100%), head tremor (67% vs. 79%), and dystonia in other body parts (23% vs. 36%) in CD-T.

CONCLUSIONS

CD-I and CD-T are clinically similar. Trauma may be a triggering factor in CD but this was only supported by non-significant trends in its earlier age of onset.

The Symptom Checklist-90 Revised questionnaire: no psychological profiles in complex regional pain syndrome-dystonia

Complex regional pain syndrome (CRPS) is a syndrome usually localized in the extremities, mostly occurring after a preceding trauma or operation. Dystonia is present in a minority of CRPS patients, but, when present, leads to severe disability. Various pathological factors have been postulated to present in CRPS-dystonia, such as involvement of the sympathetic system, reorganization of the central nervous system, and psychological distress. In the present study, we investigated the involvement of psychological distress in CRPS-dystonia with the aid of the Symptom Checklist-90 Revised (SCL-90R) questionnaire. The SCL-90R is a multidimensional self-report inventory covering various dimensions of psychological distress. In a population of 1006 CRPS patients, we analyzed the SCL-90R scores of 27 patients with CRPS-dystonia (23 female and 4 male) and compared the scores to sample scores of a control female (n = 577) and a control rehabilitation population (n = 56). Insomnia scored significantly higher in the female CRPS-dystonia population, as compared to the control female population (P < 0.001), and in the total CRPS-dystonia population, as compared to the rehabilitation population (P < 0.01). Remarkable was the significantly higher score of somatization in the rehabilitation population, as compared to the CRPS-dystonia population (P = 0.006). For the other dimensions of psychological distress of the SCL-90R, the scores of the CRPS-dystonia and control populations were similar. With regard to the SCL-90R scores, we conclude that specific psychological profiles are not present in CRPS-dystonia.

Movement disorders following nonfunctional neurosurgery

OBJECT

Knowledge is scarce about movement disorders that follow neurosurgical operations other than functional stereotactic surgery. The cases of 14 patients who suffered from movement disorders secondary to craniocerebral or spinal surgery are analyzed. None of these patients was initially treated by any of the authors.

METHODS

Twelve patients underwent surgery for cerebral diseases. Nine of these patients harbored tumors and three patients had neurovascular disorders. Two patients underwent spinal surgery for cervicothoracic ependymoma or for multiple cervical disc herniations. Twelve of the 14 patients had immediate postoperative side effects such as hemiparesis, ataxia, and somnolence. In all but two patients, movement disorders became manifest only after a delay. Dystonic movement disorders developed in eight patients, unilateral tremors in three patients, unilateral facial myokymia in one patient, and hemichorea-hemiballism in two patients. The mean delay of onset for tremor was 5 weeks and that for dystonic movement disorders was 5.5 months. Movement disorders were transient in three patients; however, they were persistent in 11 patients at a mean follow-up period of 5 years. These movement disorders caused marked persistent disability in four patients. Lesions of the contralateral striatum were identified in patients with dystonic syndromes and lesions of the dentatothalamic outflow in patients with tremors. In three patients who had postoperative basal ganglia lesions after partial removal of astrocytomas, tumor regrowth was later documented. Medical treatment in patients with persistent movement disorders rendered only limited benefit. Two patients improved with botulin injections. In one patient postoperative hemidystonia was alleviated by contralateral thalamotomy.

CONCLUSIONS

Dystonic syndromes and tremors are the most common movement disorders that occur after craniocerebral and spinal surgery. Postoperative movement disorders can lead to various degrees of functional disability. The pathoanatomical correlations are similar to those described in other patients with secondary movement disorders.

Differential diagnosis of Parkinson's disease

The differential diagnosis of PD includes other neurodegenerative disorders; hereditary disorders; and symptomatic causes, such as structural lesions, infections, metabolic abnormalities, hydrocephalus, and drugs or toxins. A good history of symptom evaluation, drug use, and family illness is just as essential as a careful neurologic examination when evaluating a patient with parkinsonism. Although there is no definitive diagnostic test for PD at this time, tests to rule out other causes should be considered and then treatment started.

Rehabilitation after traumatic brain injury in adults

PURPOSE

Traumatic brain injury (TBI) stands as a major public health problem and one of the most important challenges for neurological rehabilitation. This review discusses advances that have occurred in the past 10 years in rehabilitation after severe TBI in adults.

METHOD

First, theoretical concepts, goals of rehabilitation and organization of resources are reviewed. Then specific questions that arise in the rehabilitation of severe TBI patients are considered.

RESULTS

Three phases are distinguished in post-traumatic evolution. Acute rehabilitation takes place during coma and arousal states. Specific aims are to prevent orthopaedic and visceral complications, and to provide sensory stimulations with the hope of accelerating arousal. Secondly subacute (generally inpatient) rehabilitation is designed to facilitate and accelerate recovery of impairments, and to compensate for disabilities. Motility, cognition, behaviour, personality and affect should be simultaneously addressed in an holistic approach. Physical as well as psychological independence and self-awareness are the major goals to emphasize. A third, post-acute rehabilitation phase includes outpatient therapy for achieving physical, domestic and social independence, reduction of handicaps and re-entry into the community.

CONCLUSIONS

Problems with returning home, obtaining financial independence, driving, returning to work, participating in social relationships and leisure activities, and the importance of psychosocial adjustment and self-acceptance, are outlined. Questions about economic aspects and rehabilitation in the future are addressed.

Peripherally induced oromandibular dystonia

OBJECTIVES

Oromandibular dystonia (OMD) is a focal dystonia manifested by involuntary muscle contractions producing repetitive, patterned mouth, jaw, and tongue movements. Dystonia is usually idiopathic (primary), but in some cases it follows peripheral injury. Peripherally induced cervical and limb dystonia is well recognised, and the aim of this study was to characterise peripherally induced OMD.

METHODS

The following inclusion criteria were used for peripherally induced OMD: (1) the onset of the dystonia was within a few days or months (up to 1 year) after the injury; (2) the trauma was well documented by the patient's history or a review of their medical and dental records; and (3) the onset of dystonia was anatomically related to the site of injury (facial and oral).

RESULTS

Twenty seven patients were identified in the database with OMD, temporally and anatomically related to prior injury or surgery. No additional precipitant other than trauma could be detected. None of the patients had any litigation pending. The mean age at onset was 50.11 (SD 14.15) (range 23-74) years and there was a 2:1 female preponderance. Mean latency between the initial trauma and the onset of OMD was 65 days (range 1 day-1 year). Ten (37%) patients had some evidence of predisposing factors such as family history of movement disorders, prior exposure to neuroleptic drugs, and associated dystonia affecting other regions or essential tremor. When compared with 21 patients with primary OMD, there was no difference for age at onset, female preponderance, and phenomenology. The frequency of dystonic writer's cramp, spasmodic dysphonia, bruxism, essential tremor, and family history of movement disorder, however, was lower in the post-traumatic group (p<0.05). In both groups the response to botulinum toxin treatment was superior to medical therapy (p<0.005). Surgical intervention for temporomandibular disorders was more frequent in the post-traumatic group and was associated with worsening of dystonia.

CONCLUSION

The study indicates that oromandibular-facial trauma, including dental procedures, may precipitate the onset of OMD, especially in predisposed people. Prompt recognition and treatment may prevent further complications.

Pharmacologic management of movement disorder after midbrain haemorrhage

Movement disorders following midbrain haemorrhage are infrequently encountered in rehabilitation, and are uncommonly corrected by pharmacologic means. This report describes a 20 year-old male with a prior history of cocaine abuse who presented with a 4 day history of dysarthria and blurred vision following methamphetamine abuse. Physical examination demonstrated hypertension, left facial hemispasm, bilateral upward gaze paresis and ataxic gait. Magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) showed multifocal parenchymal haematomas in the mesencephalic tegmentum, subcortical left front region and right anterior thalamus consistent with cavernous angiomas. The patient was transferred to rehabilitation on hospital day 5. The following day, he developed choreoathetoid movements, dystonia, and aphasia, secondary to an extension of the midbrain haemorrhage. Cogentin was initiated with slight improvement in choreoathetoid movements. The patient began intensive multidisciplinary rehabilitation therapy but after 18 days of therapy, the patient remained totally dependent in activities of daily living (ADLs), transfers, mobility and was unable to communicate in any manner. A trial of Sinemet was initiated, with resultant steady improvement in functional ability over the next month. By discharge, the patient was independent in ADLs and ambulation. By 9 months post discharge follow-up, the patient was fully independent with normal cognition, and had self tapered all medications without ill effect. Dopamine agonist trials of appropriate duration appear indicated in cases of movement disorder (paucity or excess) following midbrain lesions.

Bradykinesia and bradyphrenia revisited: patterns of subclinical deficit in motor speed and cognitive functioning in head-injured patients with good recovery

Twenty-four patients, showing a good clinical recovery from coma-inducing injury and coping well with the activities of everyday living, were tested, at least 1 year after trauma, on motor speed and reaction time, and given a neuropsychological examination. While the patients generally performed within the normal range on the neuropsychological tests, their motor speeds and reaction times--both simple (SRT) and complex (CRT)--were significantly slower than those of matched controls. This points to a subclinical bradykinesia. The patients' motor speed scores did not correlate significantly with any of the neuropsychological tests; nor did SRT or CRT. While the difference between simple and complex reaction time was significantly greater in the patient group, the percentage difference was not significantly different between the two groups. Collectively, these results suggest that bradykinesia and bradyphrenia do not necessarily overlap. Finally, there was no significant correlation between motor performance and severity of original injury, whether the latter was measured by number and size of lesions or by duration of post-traumatic amnesia.

Genetic and environmental risk factors in Parkinson's disease

Parkinson's disease (PD) is a multifactorial disorder, caused by a combination of age, genetics and environmental factors. Nigral cells are susceptible to multiple causes of derangement of normal cell function, all of which may contribute to the same Parkinson phenotype. Autosomal dominant alpha-synuclein-gene PD represents one of the pure genetic forms, whereas cases of sporadic PD probably depend more on age and environmental factors, MPTP-Parkinsonism being the purest example of an environmentally caused Parkinson phenotype. This review suggests that pesticides-herbicides, smoking and head trauma probably represent the most eligible candidates for environmental factors involved in provoking PD or influencing its natural course.

Delayed segmental axial dystonia of the trunk on standing after lumbar disk operation

We report four patients with various degrees of chronic, tonic, mildly painful, or non-painful, kyphoscolioses in orthostatism, which developed weeks, or months, after one or several laminectomies for lumbar disk hernia, in the absence of recurring radicular pain or acute lumbar pain. No family history or personal antecedent, of focal or generalized dystonia was found and the dystonia was not seen in any of the four patients pre-operatively, or during the immediate post-operative period. Only ill-defined lumbar 'discomfort', unlike their pre-operative lumbago, was reported by the patients, before and during the occurrence of the pathologic trunk posture on standing. Asymmetric lumbar muscle tonic contraction and hypertrophy was found on physical examination. In all patients, the kyphoscoliosis was maximal when standing, partially disappeared when seated, and completely when lying down. One patient responded well to clonazepam, but the other three showed no improvement with either clonazepam or local injections of botulinum toxin; L-dopa was ineffective in all cases, and trihexiphenidyle in three.

Tics secondary to craniocerebral trauma

We describe three adult patients who presented with multifocal motor and vocal tics secondary to craniocerebral trauma. In one case, the tics were accompanied by marked obsessive-compulsive behavior. All patients were involved in motor vehicle accidents resulting in closed craniocerebral trauma. The latency of onset between head trauma and the movement disorder varied between 1 day and a few months. Magnetic resonance imaging, which was performed in all three patients, did not detect any structural lesions of the basal ganglia or the brainstem. Extensive bifrontal leukoencephalopathy was found in one patient who suffered severe head trauma.

Posttraumatic movement disorders after moderate or mild head injury

We examined the occurrence of posttraumatic movement disorders after moderate or mild head injury with a three-level follow-up study including questionnaires, telephone interviews, and personal examinations 4-6 years after the trauma (mean 5.2 years). Sixteen of 158 patients (10.1%) for whom a detailed follow-up was available had developed movement disorders most probably related to craniocerebral trauma. The most frequent finding was a low-amplitude postural/intention tremor that appeared to resemble enhanced physiological or essential tremor. Twelve patients reported transient tremor, two patients had persistent tremor, one patient had transient tremor and persistent hyperekplexia, and another patient had mild persistent cervical myoclonic twitches. Overall, the movement disorder was transient in 12 patients (7.6%) and persisted in only 4 patients (2.6%). These movement disorders were not disabling and did not require medical therapy. Taking into account possible bias by selection of the sample group, the frequency of movement disorders secondary to moderate or mild head trauma might be lower than 10.1%. Posttraumatic movement disorders occurred significantly more often in the group of patients with Glasgow Coma Scores between 9 and 14 than in those with a score of 15. Severe movement disorders such as low-frequency kinetic tremor or hemidystonia were not identified in this survey.

Environmental and genetic risk factors in Parkinson's disease: a case-control study in southern Italy

To clarify the role of heredity and of some environment risk factors in the etiology of idiopathic Parkinson's disease, we performed a case-control study in two regions of southern Italy, Campania and Molise. We selected two controls for each parkinsonian patient, the patient's spouse and a sex- and age-matched neurological control. One hundred sixteen consecutive outpatients with Parkinson's disease (77 men, 39 women; mean age +/- SD = 62.5 +/- 9.9) and the same number of spouses and neurological controls were interviewed about five environmental risk factors (cigarette smoking, well-water drinking, head trauma with loss of consciousness, strict diets, general anesthesia) and two genetic risk factors (family history of Parkinson's disease or of essential tremor). Well-water drinking and family history of Parkinson's disease or essential tremor showed a positive association with Parkinson's disease; smoking showed a negative association. The most relevant risk factor was history of familial Parkinson's disease (odds ratio = 14.6; 95% confidence interval = 7.2 - 29.6); 33% of our patients had at least one affected relative. We also showed a unilateral distribution of ancestral secondary cases on the paternal or on the maternal side, which suggests a dominant inheritance. Clinical and epidemiologic features of cases with familial Parkinson's disease showed no peculiarity. The study suggests a strong role of the genetic factors in the etiology of Parkinson's disease.

Epidemiology and outcome of cervical dystonia (spasmodic torticollis) in Rochester, Minnesota

The natural history of cervical dystonia (spasmodic torticollis) was investigated in a population-based study in Rochester, Minnesota. Eleven new cases were identified with onset during the 20-year period 1960-1979. The overall incidence rate was 1.2 per 100,000 person-years (95% confidence interval 0.5-1.9) with a female:male ratio of age-adjusted incidence rates of 3.6:1. A unitary etiology was not apparent: injury antedated onset in four of the 11 patients, whereas six had documented thyroid disease and four had diabetes. A family history of movement disorder was recorded for only one subject. Only one of the cases would have been classified as moderate in severity; the others were mild. In follow-up through 1993, progressive disability was noted in only two patients, and two others went into remission. Three cases of intracranial aneurysm were confirmed, two of which produced fatal subarachnoid hemorrahage. A third death was due to amyotrophic lateral sclerosis.

Psychogenic dystonia: a review of 18 cases

OBJECTIVE

To review the clinical characteristics and associated features found in patients with psychogenic dystonia.

METHODS

A 10 year retrospective chart review of all patients diagnosed by the author as having psychogenic dystonia.

RESULTS

Eighteen patients fulfilled diagnostic criteria for "Documented" or "Clinically Established" psychogenic dystonia. Clinical characteristics of the dystonia were inconsistent or incongruous with established forms of organic dystonia. Fourteen of the 18 patients had a known precipitant. In most, the onset was abrupt and progression occurred rapidly, often to fixed dystonic postures. In contrast to idiopathic dystonia, involvement of the legs was common (12 patients), despite onset in adult life. Although cases of isolated paroxysmal dystonia were excluded in the review, 10 patients had paroxysmal worsening of dystonia or other abnormal movements. Pain was a prominent feature in 14 of 16 patients with the complaint and 1 patient with documented psychogenic dystonia also had well established reflex sympathetic dystrophy (RSD). Other psychogenic movement disorders, psychogenic neurological signs and multiple somatizations were common. Long-term follow up was available for less than one-half of the patients. Outcome varied considerably; some patients had complete resolution of symptoms (including 1 who had undergone 2 previous thalamotomies) and others remained disabled by persistent dystonia.

CONCLUSIONS

Dystonia is uncommonly due to primary psychological factors. At times this is an extremely difficult diagnosis to make and even when the diagnosis is confirmed, management remains very challenging. Future studies are required in hopes of providing more efficient means of distinguishing psychogenic dystonia from other dystonic syndromes especially those which rarely follow peripheral injury or accompany RSD/causalgia syndromes.

Unusual focal dyskinesias: the ears, the shoulders, the back, and the abdomen

Fourteen patients with focal or segmental involuntary movements affecting the ears, back, shoulder girdle, and upper extremity, as well as the abdomen and pelvic girdle, are presented. The unusual locations and appearance of these dyskinesias distinguishes them from recognized movement disorder syndromes. It is argued that the slow, sinuous, and semirhythmic character of the movements and the variable long-duration bursts of motor unit activity responsible for them most closely fit into the spectrum of dystonia. A history of pain in the affected region and/or peripheral trauma in some cases also suggests that peripheral factors may play a role in their pathogenesis.

The treatment of posttraumatic tremor by stereotactic surgery. Symptomatic and functional outcome in a series of 35 patients

The authors report the long-term results of stereotactic surgery for severe posttraumatic appendicular tremor in 35 patients. The tremors developed after severe head trauma in 33 patients (94%) and after mild to moderate head trauma in two (6%). In all but one, the tremor was most evident during activity. The amplitude of the kinetic tremor was greater than 5 cm in 33 patients (94%) and greater than 12 cm in 19 patients (54%). All were severely incapacitated in their daily living activities due to the tremors. The 35 patients underwent 42 stereotactic operations; five patients were reoperated on the same side and two were treated with a bilateral staged procedure. The contralateral zona incerta was the stereotactic target in 12 patients and was targeted in combination with the base of the ventrolateral (oroventral) thalamus in 23 patients. Long-term postoperative follow-up review was obtained in 32 patients (mean follow-up period 10.5 years). Persistent improvement of tremor was noted in 88%. The tremor was absent or markedly reduced in 65%. Functional disability was assessed and quantified with a modified form of an established rating scale for patients with tremor; it was reduced from a mean value of 57% of maximum disability to 37% over the long term (p < 0.001). Follow-up lesion assessment was obtained in 18 patients by multiplanar magnetic resonance imaging and at autopsy in one patient whose death was unrelated to surgery. As in previous studies, the frequency of persistent side effects was relatively high (38%). These consisted mainly of aggravation of preoperative symptoms. The results are compared to those of a total of 55 patients reported from 1960 to 1992. The occurrence of dystonia and dystonic postures is discussed. Stereotactic surgery is a powerful tool to alleviate posttraumatic tremor and to improve functional disability. However, as there is considerable risk of persistent morbidity in patients after severe head trauma, the operation should be restricted to selected cases with disabling tremor.

Risk-factors for Parkinson's disease: case-control study in the province of Cáceres, Spain

This case-control study, performed in a mixed rural and urban province, of 74 patients with Parkinson's disease (PD) and 148 unselected age and sex-matched controls, attempted to look possible risk factors for PD. Rural living, well-water drinking, positive family history for PD and postural tremor, were associated to an increased risk for PD, with results regarding exposure to pesticides near to statistical significance. Alcohol-drinking habit in males were associated to a decreased risk for PD, with results regarding cigarette-smoking habit in males near to statistical significance. We did not find association between the risk for PD and the following variables: 1) exposure to industrial toxins; 2) agricultural work; 3) cranial trauma; 4) previous common illnesses including some infections, arterial hypertension, diabetes mellitus, coronary heart disease and thyroid disease; 5) coffee and tea drinking habits.

Posttraumatic cervical dystonia

Posttraumatic cervical dystonia has been described as a distinct syndrome with some similarities to idiopathic nontraumatic cervical dystonia (torticollis). We describe five patients in whom cervical dystonia developed immediately after relatively mild trauma to the neck. Four of the five patients had persistent contractions of all cervical muscles including the trapezius muscles, which almost completely prevented motion of the neck and resulted in muscle hypertrophy. The condition persisted unabated in all patients for the entire period of follow-up (duration, 1 1/2 to 3 years). Pharmaceutical interventions, which had been used previously for idiopathic nontraumatic cervical dystonia, failed to benefit these patients. Two patients who received injections of botulinum toxin had no more than mild benefit. Selective denervation was inapplicable because of the widespread involvement of all cervical muscles in all but one patient. Physical therapy was essentially ineffective. Because of the unusual features and possible medicolegal setting, clinicians may tend to diagnose this condition as a psychogenic disorder or litigation-oriented behavior. The clinical picture, however, is consistent with an organic dystonia that may render the patient functionally and occupationally disabled.