Persistence of tropical ataxic neuropathy in a Nigerian community.
(1/54)
OBJECTIVES: The term tropical ataxic neuropathy (TAN) is currently used to describe several neurological syndromes attributed to toxiconutritional causes. However, TAN was initially proposed to describe a specific neurological syndrome seen predominantly among the Ijebu speaking Yorubas in south western Nigeria. In this study, the prevalence of TAN was determined in Ososa, a semiurban community in south western Nigeria described as endemic for TAN in 1969, and its neurological features were compared with Strachan's syndrome, prisoners of war neuropathy, the epidemic neuropathy in Cuba, and konzo. METHODS: A census of Ososa was followed by door to door screening of all subjects aged 10 years and above with a newly designed screening instrument. Subjects who screened positive had a neurological examination, and the diagnosis of TAN was made if any two or more of bilateral optic atrophy, bilateral neurosensory deafness, sensory gait ataxia, or distal symmetric sensory polyneuropathy were present. RESULTS: A total of 4583 inhabitants were registered in the census. Of these, 3428 subjects aged 10 years and above were screened. The diagnosis of TAN was made in 206 of 323 subjects who screened positive for TAN. The prevalence of TAN was 6. 0%, 3.9% in males and 7.7% in females. The highest age specific prevalence was 24% in the 60-69 years age group in women. CONCLUSION: The occurrence of TAN in Ososa continues at a higher prevalence than was reported 30 years ago. Its neurological features and natural history do not resemble those described for Strachan syndrome, epidemic neuropathy in Cuba, or konzo. The increasing consumption of cassava foods linked to its causation makes TAN of public health importance in Nigeria, the most populous African country. (+info)
Turning difficulty characteristics of adults aged 65 years or older.
(2/54)
BACKGROUND AND PURPOSE: Falls that occur while walking have been associated with an increased risk of hip fracture in elderly people. This study's purpose was to describe movement characteristics in older adults that serve as indicators of difficulty in turning while walking. SUBJECTS: Three groups were assessed: young adults who had no difficulty in turning (age range=20-30 years, n=20) (YNDT group), elderly adults who had no difficulty in turning (age range=65-87 years, n=15) (ENDT group), and elderly adults who had difficulty in turning (age range=69-92 years, n=15) (EDT group). METHODS: All subjects were videotaped performing a self-paced 180-degree turn during the Timed "Up & Go" Test. Movement characteristics of each group were identified. Four characteristics were used to identify difficulty in turning: (1) the type of turn, (2) the number of steps taken during the turn, (3) the time taken to accomplish the turn, (4) and staggering during the turn. RESULTS: In general, the EDT group took more steps during the turn and more time to accomplish the turn than the YNDT and ENDT groups. Although the only turning strategy used by the YNDT group was a pivot type of turn, there was an almost total absence of a pivot type of turn in the EDT group. No differences were found among the groups on the staggering item, yet the EDT group was the only group in which staggering was present. We believe these changes observed in the 4 characteristics only in the EDT group are indicators of difficulty in turning while walking. CONCLUSION AND DISCUSSION: These indicators of difficulty may be useful for the early identification of individuals aged 65 years or older who are having difficulty in turning and may well serve as the basis for the development of a scale for difficulty in turning in older adults. Preliminary findings indicate the need for further study into the reliability, validity, and sensitivity of measurements obtained with such a scale. (+info)
Metastatic brainstem tumor manifesting as hearing disturbance--case report.
(3/54)
A 53-year-old male, who had undergone a left upper lung lobectomy for cancer 2 years previously, presented with metastatic brainstem tumor manifesting as hearing disturbance. At first an otorhinolaryngologist treated him for senile sensorineural hearing disturbance. However, he suffered gait ataxia and was referred to our department. On admission, neurological examination found mild cerebellar ataxia on the left and gait unsteadiness. Neurootological analysis revealed central-type sensorineural hearing disturbance on the left both in the pure tone audiogram and speech discrimination test. Neuroimaging studies revealed a ring-like enhanced mass centered in the ventral left middle cerebellar peduncle, partly extending to the inferior cerebellar peduncle. Peritumoral edema extending to the ipsilateral cochlear nucleus was recognized. He underwent surgery via a left lateral suboccipital transcondylar approach. The histological diagnosis was adenocarcinoma identical with the primary lung cancer. Intra-axial brainstem metastatic lesion can be a cause of hearing disturbance, so should be included in the differential diagnosis for a patient complaining of hearing disturbance, especially with a past history of cancer. (+info)
Polyglutamine-expanded ataxin-7 promotes non-cell-autonomous purkinje cell degeneration and displays proteolytic cleavage in ataxic transgenic mice.
(4/54)
Spinocerebellar ataxia (SCA) type 7 is an inherited neurodegenerative disorder caused by expansion of a polyglutamine tract within the ataxin-7 protein. To determine the molecular basis of polyglutamine neurotoxicity in this and other related disorders, we produced SCA7 transgenic mice that express ataxin-7 with 24 or 92 glutamines in all neurons of the CNS, except for Purkinje cells. Transgenic mice expressing ataxin-7 with 92 glutamines (92Q) developed a dramatic neurological phenotype presenting as a gait ataxia and culminating in premature death. Despite the absence of expression of polyglutamine-expanded ataxin-7 in Purkinje cells, we documented severe Purkinje cell degeneration in 92Q SCA7 transgenic mice. We also detected an N-terminal truncation fragment of ataxin-7 in transgenic mice and in SCA7 patient material with both anti-ataxin-7 and anti-polyglutamine specific antibodies. The appearance of truncated ataxin-7 in nuclear aggregates correlates with the onset of a disease phenotype in the SCA7 mice, suggesting that nuclear localization and proteolytic cleavage may be important features of SCA7 pathogenesis. The non-cell-autonomous nature of the Purkinje cell degeneration in our SCA7 mouse model indicates that polyglutamine-induced dysfunction in adjacent or connecting cell types contributes to the neurodegeneration. (+info)
Typical features of cerebellar ataxic gait.
(5/54)
BACKGROUND: Although gait disturbance is one of the most pronounced and disabling symptoms in cerebellar disease (CD), quantitative studies on this topic are rare. OBJECTIVES: To characterise the typical clinical features of cerebellar gait and to analyse ataxia quantitatively. METHODS: Twelve patients with various cerebellar disorders were compared with 12 age matched controls. Gait was analysed on a motor driven treadmill using a three dimensional system. A tandem gait paradigm was used to quantify gait ataxia. RESULTS: For normal locomotion, a significantly reduced step frequency with a prolonged stance and double limb support duration was found in patients with CD. All gait measurements were highly variable in CD. Most importantly, balance related gait variables such as step width and foot rotation angles were increased in CD, indicating the need for stability during locomotion. The tandem gait paradigm showed typical features of cerebellar ataxia such as dysmetria, hypometria, hypermetria, and inappropriate timing of foot placement. CONCLUSIONS: Typical features of gait in CD are reduced cadence with increased balance related variables and an almost normal range of motion (with increased variability) in the joints of the lower extremity. The tandem gait paradigm accentuates all the features of gait ataxia and is the most sensitive clinical test. (+info)
A 47-year-old alcoholic man with progressive abnormal gait.
(6/54)
Central pontine myelinolysis should be considered in the differential diagnosis of a patient with a history of alcoholism and malnutrition presenting with ataxia, regardless of serum sodium values. T2-weighted images are the most sensitive imaging technique, but changes may not be evident for weeks after the insult, and in addition, the insult may not be known. Supportive care is important to prevent complications, but no treatment has been found to be effective in treating the illness. Patient outcomes vary considerably and are difficult to predict. (+info)
Gluten ataxia in perspective: epidemiology, genetic susceptibility and clinical characteristics.
(7/54)
We previously have described a group of patients with gluten sensitivity presenting with ataxia (gluten ataxia) and suggested that this disease entity may account for a large number of patients with sporadic idiopathic ataxia. We have therefore investigated the prevalence of gluten sensitivity amongst a large cohort of patients with sporadic and familial ataxia and looked at possible genetic predisposition to gluten sensitivity amongst these groups. Two hundred and twenty-four patients with various causes of ataxia from North Trent (59 familial and/or positive testing for spinocerebellar ataxias 1, 2, 3, 6 and 7, and Friedreich's ataxia, 132 sporadic idiopathic and 33 clinically probable cerebellar variant of multiple system atrophy MSA-C) and 44 patients with sporadic idiopathic ataxia from The Institute of Neurology, London, were screened for the presence of antigliadin antibodies. A total of 1200 volunteers were screened as normal controls. The prevalence of antigliadin antibodies in the familial group was eight out of 59 (14%), 54 out of 132 (41%) in the sporadic idiopathic group, five out of 33 (15%) in the MSA-C group and 149 out of 1200 (12%) in the normal controls. The prevalence in the sporadic idiopathic group from London was 14 out of 44 (32%). The difference in prevalence between the idiopathic sporadic groups and the other groups was highly significant (P < 0.0001 and P < 0.003, respectively). The clinical characteristics of 68 patients with gluten ataxia were as follows: the mean age at onset of the ataxia was 48 years (range 14-81 years) with a mean duration of the ataxia of 9.7 years (range 1-40 years). Ocular signs were observed in 84% and dysarthria in 66%. Upper limb ataxia was evident in 75%, lower limb ataxia in 90% and gait ataxia in 100% of patients. Gastrointestinal symptoms were present in only 13%. MRI revealed atrophy of the cerebellum in 79% and white matter hyperintensities in 19%. Forty-five percent of patients had neurophysiological evidence of a sensorimotor axonal neuropathy. Gluten-sensitive enteropathy was found in 24%. HLA DQ2 was present in 72% of patients. Gluten ataxia is therefore the single most common cause of sporadic idiopathic ataxia. Antigliadin antibody testing is essential at first presentation of patients with sporadic ataxia. (+info)
Relative contributions of balance and voluntary leg-coordination deficits to cerebellar gait ataxia.
(8/54)
Different cerebellar regions participate in balance control and voluntary limb coordination, both of which might be important for normal bipedal walking. We wanted to determine the relative contributions of balance versus leg-coordination deficits to cerebellar gait ataxia in humans. We studied 20 subjects with cerebellar damage and 20 control subjects performing three tasks: a lateral weight-shifting task to measure balance, a visually guided stepping task to measure leg- coordination, and walking. We recorded three-dimensional joint position data during all tasks and center of pressure coordinates during weight-shifting. Each cerebellar subject was categorized as having no detectable deficits, a balance deficit only, a leg-placement deficit only, or both deficits. We then determined the walking abnormalities associated with each of these categories. Five of 10 measures of gait ataxia were abnormal in cerebellar subjects with a balance deficit, but only 1 was abnormal in cerebellar subjects with a leg-placement deficit. Furthermore, subjects with a balance deficit performed worse than subjects with a leg-placement deficit on 9 of the 10 gait measures. Finally, performance on the balance task, but not the leg-placement task, explained a significant proportion of the variance in walking speed for the entire cerebellar group. We conclude that balance deficits are more closely related to cerebellar gait ataxia than leg-placement deficits. Our findings are consistent with animal literature, which has suggested that cerebellar control of balance and gait are interrelated, and dissociable from cerebellar control of voluntary, visually guided limb movements. (+info)