Parkinsonism and personality changes following an acute hypoxic insult during mountaineering

balance. Gradually, she developed instability of stance and gait, slurred speech, and impaired handwriting. At age 41, backward head bend appeared, combined with disabling tremor of the head. Due to impaired visual control by retrocollis, her gait disorder worsened and she could walk only with head support allowing her to see the floor. On neurological examination, she had slight nystagmus on horizontal gaze, slurred dysarthria, severe retrocollis with dystonic head tremor, upper limb ataxia, dysmetria, and dysdiadochokinesia, predominant on the left upper limb. There were decreased reflexes and vibration sense on lower limbs. Her gait was broad-based with marked instability. Neuropsychological examination did not reveal cognitive deterioration. Video-oculography demonstrated irregular smooth pursuit movements and markedly dysmetric saccades with bilateral delay of responses. Brain MRI showed severe atrophy of cerebellar hemispheres and the brainstem. Routine biochemistry and blood count, copper metabolism, thyroid function, cerebrospinal fluid biochemistry and cell content were normal. Genetic testing proved the SCA2 genotype with 39 triplet repeats in the expanded allele (normal range, up to 31 repeats). For the disabling retrocollis and head tremor, the patient received botulinum toxin A (Dysport, 250 mU) into each of both splenii muscles that was followed by partial improvement of her cervical dystonia, without inducing dysphagia or muscular atrophy. Repeated administrations of botulinum toxin resulted in marked reduction of retrocollis with change of the dystonic pattern into rotatocollis to the right. With further progression of gait ataxia and instability, she must use a cane when walking. SCAs are a heterogenous group of diseases where slowly progressive cerebellar syndrome is often accompanied by other neurological disorders such as peripheral neuropathy, pyramidal signs, oculomotor disturbances, and cognitive deterioration. Extrapyramidal motor signs were also described, e.g., postural tremor in SCA2, -3, and -6, Parkinsonism in SCA2 and -3, dystonia in SCA3 and -6.2–5 However, dystonia was mostly present in the form of focal limb dystonia.2–5 Only single cases of cervical dystonia associated with SCA were reported in SCA3, -6, -7, and -12 or in genetically undetermined cases.6 Of interest, severe dysphagia was described after botulinum toxin injections in SCA3, most likely because of anterior horn affection in this disease.7 In SCA2, slowly progressive cerebellar gait and limb ataxia typically combine with cerebellar dysarthria, oculomotor disturbances, hyporeflexia, and decreased vibration sense in the lower limbs.8 Chorea and myoclonus were reported in association with larger repeat expansions.8,9 Also, levodopa-responsive Parkinsonism was observed in a few patients.10 Importantly, cervical dystonia was not reported previously even in large series of patients with SCA2.8,11,12 In the recent study, the occurrence of torticollis has been described in 1 (and dystonic arm posturing in three) of 9 Serbian patients with SCA2 genotype.1 In our case, we confirm that cervical dystonia can be a part of an otherwise typical SCA2 phenotype. Indeed, with regard to the rather high occurrence in Serbian patients with SCA2, the presence of dystonia might represent a specific phenotypic pattern in a subset of Eastern European populations.