Deep brain stimulation or thalamotomy in fragile X-associated tremor/ataxia syndrome? Case report.

We present the case of a 66-year-old man who has been treated for essential tremor since the age of 58. He developed mild cerebellar gait ataxia seven years after tremor onset. Moderate, global brain atrophy was identified on MRI scans. At the age of 68, only temporary tremor relief could be achieved by bilateral deep brain stimulation of the ventral intermedius nucleus of the thalamus. Bilateral stimulation of the subthalamic nucleus also resulted only in transient improvement. In the meantime, progressive gait ataxia and tetraataxia developed accompanied by other cerebellar symptoms, such as nystagmus and scanning speech. These correlated with progressive development of bilateral symmetric hyperintensity of the middle cerebellar peduncles on T2 weighted MRI scans. Genetic testing revealed premutation of the FMR1 gene, establishing the diagnosis of fragile X-associated tremor/ataxia syndrome. Although this is a rare disorder, it should be taken into consideration during preoperative evaluation of essential tremor. Postural tremor ceased two years later after thalamotomy on the left side, while kinetic tremor of the right hand also improved.

Dorsal laminectomy for treatment of cervical vertebral stenotic myelopathy in an alpaca.

CASE DESCRIPTION: An 11-year-old male breeding alpaca was evaluated for a 2-day history of lowered head carriage and lethargy. CLINICAL FINDINGS: On initial examination, the alpaca had signs of lethargy and lowered carriage of the head and neck, but no specific neurologic deficits. Medical management improved the clinical signs, but 8 months later, the alpaca developed acute, progressive general proprioceptive ataxia affecting all 4 limbs and was referred for further evaluation and treatment. Magnetic resonance imaging and CT identified disruption of the normal osseous architecture of C7 and T1. Medical management was attempted, but because of a lack of improvement, the patient underwent surgery 14 months after initial examination. TREATMENT AND OUTCOME: A dorsal laminectomy of C7 and T1 via a dorsal midline approach was performed, and the spinous processes of both vertebrae were removed prior to removal of the overlying lamina. Free dorsal expansion of the spinal cord was ensured by resection of the ligamentum flavum. Six months after surgery, the alpaca had returned to successful breeding with 7 hembra bred in the first year after surgery, producing 6 crias, and 4 crias in the second year. The patient was eventually euthanized 28 months after surgery because of neurologic deterioration but was still ambulatory at that time. CONCLUSIONS AND CLINICAL RELEVANCE: A good outcome with adequate alleviation of clinical signs and breeding soundness for > 2 years following dorsal laminectomy was achieved in this camelid patient. The surgical approach was similar to that in other species and was associated with mild postoperative morbidity. Veterinarians treating camelids should be aware of the initial clinical signs and treatment options for cervical vertebral stenotic myelopathy. In acute cases, the signs of reduced cervical mobility and pain on manipulation should prompt investigation including appropriate diagnostic imaging. Timely surgical intervention should be considered in patients that respond poorly to medical treatment to avoid irreversible spinal cord injury and optimize outcome.

Treatment for ataxia in multiple sclerosis.

BACKGROUND: Disabling tremor or ataxia is common in multiple sclerosis (MS) and up to 80% of patients experience tremor or ataxia at some point during their disease. A variety of treatments are available, ranging from pharmacotherapy or stereotactic neurosurgery to neurorehabilitation. OBJECTIVES: To assess the efficacy and tolerability of both pharmacological and non-pharmacologic treatments of ataxia in patients with MS. SEARCH STRATEGY: The following electronic resources were searched: Cochrane MS Group trials register (June 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2006), National Health Service National Research Register (NRR) including the Medical Research Council Clinical Trials Directory (Issue 2, 2006), MEDLINE (January 1996 to June 2006), and EMBASE (Jan 1988 to June 2006). Manual searches of bibliographies of relevant articles, pertinent medical and neurology journals and abstract books of major neurology and MS conferences (2001-2006) were also performed. Direct communication with experts and drug companies was sought. SELECTION CRITERIA: Blinded, randomised trials which were either placebo-controlled or which compared two or more treatments were included. Trials testing pharmacological agents must have had both participant and assessor blinding. Trials testing surgical interventions or effects of physiotherapy, where participants could not have been blinded to the treatment, must have had independent assessors who were blinded to the treatment. Cross-over trials were included. DATA COLLECTION AND ANALYSIS: Three independent reviewers extracted data and the findings of the trials were summarised. A meta-analysis was not performed due to the inadequacy of outcome measures and methodological problems with the studies reviewed. MAIN RESULTS: Ten randomised controlled trials met the inclusion criteria. Six placebo-controlled studies (pharmacotherapy) and four comparative studies (one stereotactic neurosurgery and three neurorehabilitation) were reviewed. No standardised outcome measures were used across the studies. In general, pharmacotherapies were unrewarding and data on neurosurgery or rehabilitation is insufficient to lead to a change in practice. AUTHORS' CONCLUSIONS: The absolute and comparative efficacy and tolerability of pharmacotherapies to treat ataxia in MS are poorly documented and no recommendations can be made to guide prescribing. Although studies on neurosurgery and neurorehabilitation showed promising results, the absolute indications for treating with those methods cannot be developed. Standardised, well validated measures of ataxia and tremor need to be developed and employed in larger randomised controlled trials with careful blinding.

Vim thalamotomy for Holmes' tremor secondary to midbrain tumour.

Holmes' (rubral or midbrain) tremor is an unusual combination of 2 Hz to 5 Hz rest, postural, and kinetic tremors of an upper extremity. This tremor has been considered to result from the lesions in the vicinity of the red nucleus in the midbrain. There has been no systematic analysis of the surgical target in the Holmes' tremor so far of nucleus ventrointermedius (Vim) or globus pallidus interna. This 26 year old man gradually developed a disabling midbrain tremor involving both the distal and proximal parts of the left upper arm. Additional neurological findings included oculomotor palsy and ataxia of the left arm. On the radiological studies, a mass lesion (germinoma) was found on the midbrain tegmentum, which was treated by conventional radiation therapy. Although there was improvement in the radiological imaging, his midbrain tremor became intolerable despite medical treatment. The authors performed MR guided stereotactic Vim thalamotomy. With radiofrequency lesioning in the right Vim, his resting, postural, and action tremors were much alleviated in both the distal and proximal parts of the left upper extremity. The authors consider that Vim thalamotomy is still an effective means of controlling midbrain tremors involving the proximal upper limb.

Neurosurgery in cerebral palsy.

Stereotaxic subthalamotomy of 55 patients with cerebral palsy gave a good result in 65% of the selected cases. The result was uncertain in 15 and poor in 20%. An independent socio-medical follow-up study confirmed the clinical finding. The more rapid the involuntary movements, the better was the effect of subthalamotomy. Intention tremor was the most suitable symptom for stereotaxic treatment. Rigidospasticity was alleviated in the distal muscles only. Speech and gait were often improved. Good results were obtained in patients with normal intelligence, while feeble-minded patients did not benefit from the operation. Subthalamotomy was followed by transitory side-effects in 20%, of which increased involuntary movements on the ipsilateral side and mental restlessness were the most frequent. The operation had no mortality. Spinal longitudinal myelotomy effectively relieved the spasticity of the lower limbs in the three patients operated upon.