|
| ||
|
|
||
Cerebellar Dysfunction (cerebellar + dysfunction)
Selected AbstractsAtaxia, autism, and the cerebellum: a clinical study of 32 individuals with congenital ataxiaDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 3 2005Ingegerd Åhsgren MD The suggested link between autism and cerebellar dysfunction formed the background for a Swedish clinical study in 2001. Thirty-two children (17 females, 15 males; mean age 12y, SD 3y 10mo; range 6 to 21y) with a clinical suspicion of non-progressive congenital ataxia were examined, and parents were interviewed about the presence of neuropsychiatric problems in the child. Twelve children had simple ataxia, eight had ataxic diplegia, and 12 had,borderline'ataxia. All but one of the 32 children had a mild to moderate gross motor disability according to Gross Motor Function Classification System (15 were categorized as level I,16 as level II, and one child as level IV). Neuroimaging and neuropsychological testing were achieved in most cases. There was a strong association between learning disability* and autism spectrum disorder (often combined with hyperactivity disorder) on the one hand, and both simple and borderline,ataxia'on the other, but a weaker link between ataxic diplegia and neuropsychiatric disorders. A correlation between cerebellar macropathology on neuroimaging and neuropsychiatric disorders was not supported. Congenital ataxia might not be a clear-cut syndrome of cerebellar disease, but one of many signs of prenatal events or syndromes, leading to a complex neurodevelopmental disorder including autism and learning disability. [source] Balancing and pointing tasks in dyslexic and control adultsDYSLEXIA, Issue 4 2006Catherine J. Stoodley Abstract Developmental dyslexia may affect as much as 15% of the population, but the aetiology of the disorder is still being debated. The cerebellar theory of dyslexia proposes that cerebellar dysfunction could lead to the myriad of symptoms seen in dyslexic individuals, both in literacy and non-literacy domains. The cerebellum is crucial to the fluent performance of motor skills. Previous studies have found that dyslexic children are worse than control children on certain motor and balancing tasks. Here the performance of 28 dyslexic compared to 26 control adults on rapid pointing and balancing measures, tasks which are thought to reflect cerebellar function, was investigated. There were no significant differences between the dyslexic and control participants on the balancing tasks or when the speed and accuracy of pointing were analysed separately. However, when the speed and accuracy of pointing were combined, the dyslexic participants showed poorer performance than the controls (p = 0.045). Furthermore, there were significant relationships between performance on the pointing task and literacy skills, and regression analysis showed that the error and speed of pointing contributed significantly to the variance in literacy skill. The implications for the role of the cerebellum and processing speed in dyslexia are discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Effects of Vagus Nerve Stimulation on Progressive Myoclonus Epilepsy of Unverricht-Lundborg TypeEPILEPSIA, Issue 8 2000Brien Smith Summary: Purpose: A 34-year-old woman with progressive myoclonus epilepsy of Unverricht-Lundborg type was considered for vagus nerve stimulation (VNS) therapy. Methods: After demonstration of intractability to multiple antiepileptic regimens and progressive deterioration in cerebellar function, the patient was implanted with a vagus nerve stimulator and followed for 1 year. Neurological status, seizure frequency, and parameter changes were analyzed. Results: VNS therapy resulted in reduction of seizures (more than 90%) and a significant improvement in cerebellar function demonstrated on neurological examination. The patient reported improved quality of life based in part on her ability to perform activities of daily living. Conclusions: VNS therapy may be considered a treatment option for progressive myoclonus epilepsy. The effects of VNS on seizure control and cerebellar dysfunction may provide clues to the underlying mechanism(s) of action. [source] Assessment of dementia in patients with multiple system atrophyEUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2009M. Kitayama Background and purpose:, We investigated dementia in patients with multiple system atrophy (MSA) in order to characterize the prevalence and nature of impairments in these patients. Methods:, Fifty-eight MSA patients were recruited in our institution between April 1996 and December 2006 and investigated. Results:, Of 58 patients, 10 were diagnosed with dementia. There were no significant differences in age at onset, gender, duration of disease, or severity of cerebellar dysfunction between patients with and without dementia. The early and delayed heart to mediastinum (H/M) ratios obtained with 123I-metaidobenylguanidine (MIBG) cardiac scintigraphy were significantly decreased in patients with dementia compared with those without dementia. Of the 10 patients with dementia, three were found to have cognitive decline that preceded onset of motor symptoms. White matter lesions were evident in these patients, whilst frontal atrophy was prominent in patients whose cognitive decline was preceded by onset of motor symptoms. Conclusions:, Dementia in patients with MSA may be more common than previously thought, furthermore, we speculate that clinical features of dementia in these patients might be heterogeneous. [source] Hereditary neuropathy with liability to pressure palsies associated with central nervous system myelin lesionsEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2001J. Dac Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder most commonly caused by a 1.5-Mb deletion in chromosome 17p11.2 which contains the peripheral myelin protein-22 (PMP22) gene. Mutations resulting in functional loss of one PMP22 gene copy are less frequent. We present a 51-year-old patient with a l.5-Mb deletion in chromosome 17p11.2 who exhibited signs of peripheral as well as central nervous system lesions. He gave a history of recurrent episodes of limb numbness and weakness with spontaneous but incomplete recovery since age 20. His father and two brothers had similar symptoms. Neurological examination revealed signs of multiple mononeuropathy associated with frontal lobe, corticospinal tract and cerebellar dysfunction, as well as signs of initial cognitive impairment. Electrophysiological investigations showed a demyelinating peripheral nerve disease with multiple conduction blocks and conduction disturbances in both optic nerves. Magnetic resonance imaging of the brain revealed multiple subcortical and periventricular foci of myelin lesions. The association of central and peripheral nervous system lesions in this patient indicates a possible role of PMP22 not only in peripheral but also in central nervous system myelin structure. [source] Subdural empyema and cerebellar abscess due to chronic otitis mediaINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2004K.S. Polyzoidis Summary The infratentorial variety of the subdural empyema, with or without coexisting cerebellar abscess, is a rare clinical entity that carries a high mortality rate. We briefly describe the case of a 49-year-old man presented with severe debility, fever and an obviously neglected chronic otitis media. The patient had refused surgical treatment several months ago. After admission, his level of consciousness began to deteriorate, and the radiological studies showed infratentorial subdural suppuration extending into the right cerebellar hemisphere, along with chronic pyogenic infection of the middle ear and the mastoid process. Radical mastoidectomy was performed first, followed by extensive right posterior fossa craniectomy. The two subdural collections and the cerebellar abscess were successfully evacuated. Subsequently, he received post-operative antibiotic treatment for 6 weeks. At follow-up, 10 months after surgery, his neurological recovery was complete except for a minor residual cerebellar dysfunction on the right. This unusual case highlights that in patients presented with severe intracranial complications of chronic otitis media, early diagnosis and radical surgical intervention may be life saving. [source] Inhibition of the Activity of Excitatory Amino Acid Transporter 4 Expressed in Xenopus Oocytes After Chronic Exposure to EthanolALCOHOLISM, Issue 7 2008Seung-Yeon Yoo Background:, The extracellular glutamate concentration is tightly controlled by excitatory amino acid transporters (EAATs). EAAT4 is the predominant EAAT in the cerebellar Purkinje cells. Purkinje cells play a critical role in motor coordination and may be an important target for ethanol to cause motor impairments. We designed this study to determine the effects of chronic ethanol exposure on the activity of EAAT4 and evaluate the involvement of protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3K) in these effects. Methods:, EAAT4 was expressed in Xenopus oocytes following injection of EAAT4 mRNA. Oocytes were incubated with ethanol-containing solution for 24 to 96 hours. Membrane currents induced by l -aspartate were recorded using 2-electrode voltage clamps. Responses were quantified by integration of the current trace and reported in microCoulombs (,C). Results:, Ethanol dose- and time-dependently reduced EAAT4 activity. EAAT4 activity after a 96-hour exposure was significantly decreased compared to the control values at all concentrations tested (10 to 100 mM). Ethanol (50 mM) significantly decreased the Vmax (2.2 ± 0.2 ,C for control vs. 1.6 ± 0.2 ,C for ethanol, n = 18, p < 0.05) of EAAT4 for l -aspartate. Preincubation of ethanol-treated (50 mM for 96 hours) oocytes with phorbol-12-myrisate-13-acetate (100 nM for 10 minutes) abolished the ethanol-induced decrease in EAAT4 activity. While staurosporine (2 ,M for 1 hour) or chelerythrine (100 ,M for 1 hour) significantly decreased EAAT4 activity, no difference was observed in EAAT4 activity among the staurosporine, ethanol, or ethanol plus staurosporine groups. Similarly, EAAT4 activity did not differ among the chelerythrine, ethanol, or ethanol plus chelerythrine groups. Pretreatment of the oocytes with wortmannin (1 ,M for 1 hour) also significantly decreased EAAT4 activity. However, no difference was observed in the wortmannin, ethanol, or ethanol plus wortmannin groups. Conclusions:, The results of this study suggest that chronic ethanol exposure decreases EAAT4 activity and that PKC and PI3K may be involved in these effects. These effects of ethanol on EAAT4 may cause an increase in peri-Purkinje cellular glutamate concentration, and may be involved in cerebellar dysfunction and motor impairment after chronic ethanol ingestion. [source] Cerebellar cortical abiotrophy in Lagotto Romagnolo dogsJOURNAL OF SMALL ANIMAL PRACTICE, Issue 8 2007T. S. Jokinen This case report documents two pathological variations of potentially inherited, cerebellar cortical abiotrophy in two unrelated Lagotto Romagnolo breed dogs. The first dog had an atypical lesion in the cerebellar cortex with depletion of cerebellar granular cell layer and sparing of the Purkinje cell layer. The second case had degenerative changes in both Purkinje and granular cell layers. The clinical picture was similar in both cases presented, although the severity of the signs of cerebellar dysfunction varied. [source] Elemental mercury poisoning probably causes cortical myoclonusMOVEMENT DISORDERS, Issue 13 2007Mona Ragothaman MBBS Abstract Mercury toxicity causes postural tremors, commonly referred to as "mercurial tremors," and cerebellar dysfunction. A 23-year woman, 2 years after injecting herself with elemental mercury developed disabling generalized myoclonus and ataxia. Electrophysiological studies confirmed the myoclonus was probably of cortical origin. Her deficits progressed over 2 years and improved after subcutaneous mercury deposits at the injection site were surgically cleared. Myoclonus of cortical origin has never been described in mercury poisoning. It is important to ask patients presenting with jerks about exposure to elemental mercury even if they have a progressive illness, as it is a potentially reversible condition as in our patient. © 2007 Movement Disorder Society [source] Impaired rhythm generation in essential tremorMOVEMENT DISORDERS, Issue 8 2006Zsuzsanna Farkas MD Abstract It has been suggested that the cerebellum plays a role in the event-based timing of synchronized repetitive movements. We hypothesized that regularity of rhythmic movements in essential tremor (ET) is impaired, since several lines of evidence suggest the involvement of the cerebellum in the pathomechanism of ET. To test this assumption, we examined the regularity and the maximum frequency of auditory paced repetitive movements at slow and fast stimulus rate in 34 ET patients. Variability of rhythmic finger tapping and alternating hand movements, defined by the standard deviation of movement offset before or after the pacing signal, was significantly higher compared to healthy controls. Timing of rhythmic movements of the two hands was disturbed to the same degree. Our results suggest a severe deficit of event-based rhythm generation on both sides in ET, supporting the presumed bilateral cerebellar dysfunction in this disorder. © 2006 Movement Disorder Society [source] The MAZ protein is an autoantigen of Hodgkin's disease and paraneoplastic cerebellar dysfunctionANNALS OF NEUROLOGY, Issue 1 2003Luis Bataller MD Probing a cerebellar expression library with TrAb sera from patients with Hodgkin's disease and paraneoplastic cerebellar degeneration resulted in the isolation of MAZ (myc -associated zinc-finger protein). Eleven of 19 TrAb sera and 16 of 131 controls reacted with MAZ, indicating a significant, although not specific, association between Tr and MAZ immunities (p < 0.001). Interestingly, 9 of 16 positive control patients also had cerebellar dysfunction. Purified MAZ antibodies reacted with Purkinje cells. In neuronal cells, MAZ interacts with DCC (Deleted in Colorectal Cancer product), the receptor for netrin-1, a neuronal survival factor. These findings suggest epitope spreading between the Tr antigen and the MAZ,DCC complex and offer a possible model of immune-mediated cerebellar disease. Ann Neurol 2003;53:000,000 [source] Eyeblink conditioning anomalies in bipolar disorder suggest cerebellar dysfunctionBIPOLAR DISORDERS, Issue 1 2009Amanda R Bolbecker Objectives:, Accumulating research implicates the cerebellum in non-motor psychological processes and psychiatric diseases, including bipolar disorder (BD). Despite recent evidence that cerebellar lesions have been documented to trigger bipolar-like symptoms, few studies have directly examined the functional integrity of the cerebellum in those afflicted with BD. Methods:, Using a single-cue delay eyeblink conditioning procedure, the functional integrity of the cerebellum was examined in 28 individuals with BD (9 manic, 8 mixed, and 11 euthymic) and 28 age-matched healthy controls. Results:, Analysis of the bipolar group as a whole indicated a conditioned response acquisition and timing deficit compared to controls. However, when the bipolar group was categorized according to mood state (mixed, manic, euthymic), individuals tested during mixed episodes were strikingly impaired, performing significantly worse than all other groups on both the acquisition and timing of conditioned responses. Conclusions:, These findings extend prior research implicating cerebellar functional abnormalities in BD and suggest that cerebellar dysfunction may be associated with mood state and course of illness. [source] | ||||||||||