GONADAL DYSFUNCTION IN PATIENTS WITH ATAXIA TELANGIECTASIA

ABSTRACT. Two males and three females with ataxia telangiectasia aged from 4 6/12; to 23 years were subjected to an i.v. LH-RH test. All were found to have elevated basal levels of FSH and three had elevated basal levels of LH. In all the response of FSH to LH-RH was supranormal. In the pubertal and adult females the basal levels of estradiol were low. The laboratory and clinical findings in these patients as well as data reported by others indicate that the primary gonadal failure is an integral part of AT.     

共济失调毛细血管扩张症两例患者临床与ATM基因突变研究

目的探讨共济失调毛细血管扩张症(ataxia-telangiectasia,AT)的临床特征和AFM基因的突变特点。方法应用聚合酶链反应、逆转录-聚合酶链反应、聚丙烯酰胺凝胶电泳和DNA直接测序方法对2例临床诊断AT的患者及其父母ATM基因全编码区进行突变检测。结果2例AT患者的临床特征为儿童期起病的进行性发展的小脑性共济失调,眼、皮肤毛细血管扩张以及免疫缺陷导致的反复感染;血清甲胎蛋白高于正常,免疫球蛋白：IgA、IgG值低于正常;头颅MRI显示小脑萎缩,脑SPECT显示小脑局部脑血流(rCBF)灌注减少。共发现3种碱基变异。在1例患者中发现外显子11G1346C的错义突变,为一种纯合突变;在另1例患者中发现外显子6G610T的无义突变和外显子47C6679T的错义突变,为一种复合性杂合突变。突变位点均位于ATM基因功能域。结论作出了2例AT患者的基因诊断。报道了3种新的ATM基因突变。     

Cerebellar dysfunction related to toluene sniffing

Only few cases with prolonged cerebellar symptoms after toluene sniffing have previously been reported. We describe here an 18-year-old female who inhaled pure toluene since the age of 12. She developed neurological symptoms with broad-based ataxic gait, incoordination of arms and legs, unsteadiness, dysarthria, downbeat nystagmus, bilateral positive Babinski sign, and poor concentration and abstracting ability. During her 5 weeks in hospital when she did not inhale toluene, her symptoms persisted but decreased and after 8 months had disappeared.     

A novel mutation in KCNA1 causes episodic ataxia without myokymia

We describe a unique family in which several individual are affected with episodes of ataxia that best fit the phenotype of episodic ataxia type 2 (EA2). All of the affected family members had episodes typically lasting for several hours, and none of them had muscle abnormalities including myokymia. Episodic ataxia type 1 (EA1) was not considered initially as a clinical diagnosis for the affected individuals in this family. However, by linkage mapping, sequencing and polymorphism analysis, all affecteds were found to have a novel mutation in KCNA1. Numerous missense mutations have been described previously in KCNA1 that cause EA1. The mutation c.1025G>T replaces a highly conserved serine with isoleucine at position 342 (p.Ser342Ile) in the highly conserved fifth transmembrane domain of the KCNA1. This mutation leads to a distinct clinical phenotype without myokymia broadening the scope of clinical characteristics of EA1 and highlighting the heterogeneity of phenotypic effects from distinct missense mutations.     

Enhanced intracortical inhibition in cerebellar patients

OBJECTIVE: The aim of the study was to examine intracortical excitability in cerebellar patients. METHODS: Short-latency intracortical inhibition (SICI), long-latency intracortical inhibition (LICI) and intracortical facilitation (ICF) to paired transcranial magnetic stimulation (TMS) were investigated in 8 patients with 'pure' cerebellar syndromes and in 14 age-matched normal controls. The conditioning stimulus for short-latency intracortical inhibition and intracortical facilitation was set at 70% of the resting motor threshold (RMT) and preceded the test stimulus (110-120% of the resting motor threshold) by interstimulus intervals (ISIs) of 1-30 ms. For the long-latency intracortical inhibition determinations, the conditioning stimulus was set at 120% of the resting motor threshold and preceded the test stimulus (also 120% of the resting motor threshold) by interstimulus intervals of 30-500 ms. RESULTS: No statistically significant differences were found between patients and controls as regards either short-latency intracortical inhibition or intracortical facilitation. A significant prevalence of long-latency intracortical inhibition was present in cerebellar patients at interstimulus intervals of 200-500 ms (conditioned MEP amplitude=29-41% of test MEP) as compared to controls (71-96% of test MEP). The amplitude of conditioned MEPs was persistently less than 45% of the test MEP in six patients, who were studied at interstimulus intervals up to 1000 ms. CONCLUSIONS: Long-latency intracortical inhibition was prevalent and abnormally longer-lasting in patients. Tonic hyperactivation of a subpopulation of GABAergic interneurons in the motor cortex of patients may be the mechanism responsible for this abnormality. Our findings seem to be specific to cerebellar diseases and are the opposite of those found in movement disorders such as dystonia and Parkinson's disease. These data suggest that the cerebellum and the basal ganglia may have opposite influences in tuning the excitability of the motor cortex.     

Intravenous immunoglobulin therapy for acute cerebellar ataxia

A case of acute cerebellar ataxia without any prodromal illness showed cerebellar hypoperfusion on 123 I-iodoamphetamine single photon emission computed tomography. The symptoms did not resolve spontaneously or with methylprednisolone pulse therapy but disappeared rapidly with intravenous immunoglobulin therapy.

Conclusion: Intravenous immunoglobulin therapy is worth considering in acute cerebellar ataxia that does not respond to high-dose steroid therapy.     

Central-peripheral sensory axonopathy in a juvenile case of Alpers-Huttenlocher disease

Peripheral ataxia is reported in a juvenile case of Alpers-Huttenlocher disease (AHD). Neurophysiological and neuropathological investigations revealed a central-peripheral axonopathy, affecting the deep sensation carried by the peripheral nerve fibres and the posterior tracts of the cord, due to neuronal loss of the sensory ganglia. Involvement of the sensory pathways is regarded as a major feature of juvenile AHD. Received: 28 October 2002, Received in revised form: 2 January 2003, Accepted: 15 January 2003 Present address: A. Polo, MD, Neurology Unit, Hospital of Piove di Sacco (PD), Italy Correspondence to: A. Simonati, MD     

The clinical and MRI correlate of ischaemia in the ventromedial midbrain: Claude's syndrome

The eponymous syndrome of Claude is caused by a lesion of the red nucleus and adjacent third nerve nucleus, resulting in the combination of an ipsilateral oculomotor palsy and contralateral ataxia. The MRI correlate of this syndrome has only occasionally been described. We present three cases with MRI findings which confirm the association of this clinical syndrome with infarction of the ventromedial midbrain. The coexistence of hypertension and small vessel ischaemia in two cases suggests this type of infarct may arise as a result of small vessel disease. Received: 26 September 2000, Received in revised form: 11 April 2001, Accepted: 23 April 2001