Onur Melen

Multifocal central nervous system damage caused by toluene abuse.

Four toluene abusers had evidence of severe multifocal central nervous system damage. Impairment of cognitive, cerebellar, brainstem, auditory, and pyramidal tract function, as well as CT evidence of cerebral cortical, cerebellar, and brainstem atrophy, have been noted. In addition, we found opsoclonus, ocular flutter, and ocular dvsmetria. All three patients tested had abnormal brainstem auditory evoked potentials, indicative of brainstem dysfunction. The patient with opsoclonus had CT evidence of brainstem, cerebellar, and cerebral cortical atrophy.

Identification of TMEM230 mutations in familial Parkinson's disease

Parkinsons disease is the second most common neurodegenerative disorder without effective treatment. It is generally sporadic with unknown etiology. However, genetic studies of rare familial forms have led to the identification of mutations in several genes, which are linked to typical Parkinsons disease or parkinsonian disorders. The pathogenesis of Parkinsons disease remains largely elusive. Here we report a locus for autosomal dominant, clinically typical and Lewy body–confirmed Parkinsons disease on the short arm of chromosome 20 (20pter-p12) and identify TMEM230 as the disease-causing gene. We show that TMEM230 encodes a transmembrane protein of secretory/recycling vesicles, including synaptic vesicles in neurons. Disease-linked TMEM230 mutants impair synaptic vesicle trafficking. Our data provide genetic evidence that a mutant transmembrane protein of synaptic vesicles in neurons is etiologically linked to Parkinsons disease, with implications for understanding the pathogenic mechanism of Parkinsons disease and for developing rational therapies.

Amantadine for freezing of gait in patients with Parkinson disease.

BackgroundFreezing of gait (FOG) is a common symptom in patients with advanced Parkinson’s disease (PD) representing a major cause of disability and falls. Although the pathophysiology of FOG remains poorly understood, nondopaminergic pathways have been implicated. Treatment studies of levodopa and selegiline have shown limited benefit for FOG. Limited data suggest that amantadine, an N-methyl-D-aspartate receptor antagonist, may be beneficial for FOG in PD. ObjectiveTo examine the relationship between treatment with oral amantadine and FOG in patients with PD. MethodsWe conducted a retrospective chart review of PD patients who received amantadine specifically for FOG and had a follow-up assessment of FOG. The primary outcome measure was self-reported effectiveness of amantadine (improvement, worsening, or no change in FOG) based on records from the follow-up assessment. ResultsEleven patients with PD with median age of PD onset of 67 years (range, 51–84 years) and median Hoehn and Yahr stage 3 (range, 2–4) met the study population selection criteria. Ten of 11 patients reported improvement in FOG after initiation of amantadine, whereas FOG worsened in one patient. Median amantadine dosage was 100 mg twice daily, and treatment duration was 20 months (range, 6–66 months). Four patients reported reduction in benefit after 4 months. Three patients reported adverse effects, including blurred vision, visual hallucinations, and peripheral edema; the latter 2 effects resulted in discontinuation of amantadine. ConclusionAmantadine is associated with self-reported improvement in FOG in PD, but this effect may be transient. Further studies, including a randomized placebo-controlled trial, are needed to better evaluate this association.

Susac syndrome with transient inverted vision

Susac syndrome is a triad of subacute encephalopathy, branch retinal artery occlusions, and sensorineural hearing loss caused by autoimmune microangiopathy and infarction of the brain, retina, and cochlea.1 It primarily affects young women and usually remits within 2 years, but long-term sequelae occur.1 We report a patient with Susac syndrome who sought treatment for transient inverted vision. A 41-year-old woman had multiple episodes of alternating hemiparesis, lasting 30 minutes, occurring infrequently during a 3-month period. She then experienced the sudden perception of complete inversion of the visual world, with a sensation that her surroundings were upside down. This was accompanied by nausea, vertigo, left facial numbness, and dysarthria that lasted 3 hours. The visual illusion recurred twice, the latter two episodes accompanied by the illusion of looking through a kaleidoscope. There was no headache. Initial neurologic examination was normal except …

Visual disturbances in migraine

Abnormal visual sensations are the most common and characteristic features of migraine. In some patients, they are the only features. The major visual disturbance associated with migraine is scotoma; less common are distortions in size, shape, and color of viewed objects; photophobia; and diplopia and polyopia. Sudden loss of vision occurs in retinal migraine, and paralysis, usually of the third nerve, in ophthalmoplegic migraine. Paresis also may be found with cluster headache.

Neuro-ophthalmological Complications of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Abstract Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) can lead to prominent nerve hypertrophy, which can mimic other forms of neuropathy radiologically. Neuro-ophthalmological complications can also occur in CIDP, either at presentation or chronically in the disorder. This can also cause diagnostic difficulties. We report three cases of neuro-ophthalmological complications of CIDP: two cases of papilloedema and one case of proptosis. In all three cases cranial nerve hypertrophy was present. CIDP should be considered in neuro-ophthalmological presentations associated with cranial/spinal nerve root hypertrophy.

Two common neuroophthalmic problems. Optic neuritis and transient visual disturbances

Optic neuritis and transient visual disturbances are common and challenging neuro-ophthalmic problems. Optic neuritis may occur during the course of several neurologic and systemic disorders and is characterized by reversible central visual loss. In many patients, signs and symptoms of multiple sclerosis occur after an episode of optic neuritis. Although several risk factors for development of multiple sclerosis have been identified, the relationship between optic neuritis and multiple sclerosis is still controversial. Transient visual disturbances may take the form of visual loss or visual hallucinations. In many cases, the cause of transient visual loss is never found. Hallucinations of ocular origin, however, are easily diagnosed by a thorough eye examination.

Anomalous Origin of the Ophthalmic Artery in a Patient with Amaurosis Fugax

Ectopic origin of the ophthalmic artery from the middle meningeal artery was found in a patient with amaurosis fugax. The origin of the external carotid artery on the symptomatic side was markedly stenotic. The patients symptoms disappeared after external carotid endarterectomy. We review the ectopic sites of the ophthalmic artery and discuss atheromatous disease of the external carotid system as a cause of transient ischemic attacks.