Signs Of Cerebellar Dysfunction Research Articles

Primary Coenzyme Q10 Deficiency-Related Ataxias.

Cerebellar ataxia is a neurological syndrome characterized by the imbalance (e.g., truncal ataxia, gait ataxia) and incoordination of limbs while executing a task (dysmetria), caused by the dysfunction of the cerebellum or its connections. It is frequently associated with other signs of cerebellar dysfunction, including abnormal eye movements, dysmetria, kinetic tremor, dysarthria, and/or dysphagia. Among the so-termed mitochondrial ataxias, variants in genes encoding steps of the coenzyme Q10 biosynthetic pathway represent a common cause of autosomal recessive primary coenzyme Q10 deficiencies (PCoQD)s. PCoQD is a potentially treatable condition; therefore, a correct and timely diagnosis is essential. After a brief presentation of the illustrative case of an Italian woman with this condition (due to a novel homozygous nonsense mutation in COQ8A), this article will review ataxias due to PCoQD.

Clinical, Cognitive and Behavioural Assessment in Children with Cerebellar Disorder

Cerebellar disorders are characterised clinically by specific signs and symptoms, often associated with neurodevelopmental disorder. While the clinical signs of cerebellar disorders are clearly recognisable in adults and have a precise anatomo-functional correlation, in children the semiotics are less clear and vary with age because of the particular nature of the cerebellum’s maturation. Unlike other structures of the central nervous system, this begins at a later stage of foetal development and extends over a longer period of time, even after birth. As a result, the typical signs of cerebellar dysfunction will only become evident when the cerebellar functions have become integrated into the complex circuits of the central nervous system. This means that poor motor coordination in the very early years of life may not necessarily correlate with cerebellar dysfunction, and this may also be encountered in healthy children. The cerebellum’s role in cognitive and emotional functions relies on its structure and the complexity of its connections. Cognitive and behavioral impairment in cerebellar disorders can be the results of acquired lesions or the action of genetic and environmental risk factors, to which the cerebellum is particularly vulnerable considering its pattern of development. In the pathological setting, early evidence of cerebellar damage may be very vague, due, partly, to spontaneous compensation phenomena and the vicarious role of the connecting structures (an expression of the brain’s plasticity). Careful clinical assessment will nonetheless enable appropriate instrumental procedures to be arranged. It is common knowledge that the contribution of neuroimaging is crucial for diagnosis of cerebellar conditions, and neurophysiological investigations can also have a significant role. The ultimate goal of clinicians is to combine clinical data and instrumental findings to formulate a precise diagnostic hypothesis, and thus request a specific genetic test in order to confirm their findings, wherever possible.

Clinical differences in patients with Parkinson’s disease according to tandem gait performance

Some of patients with Parkinson’s disease (PD) have abnormal tandem gait (TG) performance without any symptoms and signs of cerebellar dysfunction. Clinical difference between patients with good and poor TG performance has not yet been studied. We report the relationship between tandem gait performance and clinical characteristics including 37 patients with PD who had no evidence of cerebellar dysfunction. Using tandem gait test, the patients were divided into two groups (good-TG and poor-TG). We evaluated the two groups with Montreal Cognitive Assessment (MoCA), Mini Mental Status Examination (MMSE), Frontal Assessment Batter (FAB), Beck Depression Index (BDI-II), REM Sleep Behavior Disorder Single-Question Screen (RBD1Q), MDS-UPDRS items related to axial disability and freezing. Fifteen participants were classified as good-TG group and 22 were as poor-TG group. Participants in good-TG group had higher MoCA score and lower BDI-II score. The proportion of participants who answered “yes” to RBD1Q was lower in good-TG group (27%, 4 of 15) than that in poor-TG group (55%, 12 of 22). All participants in good-TG group marked “0” for the MDS-UPDRS item 2.13 which addresses freezing event over the past week, whereas 18% (4 of 22) of participants in poor-TG group marked “1”. In conclusion, tandem gait performance may be related to various clinical characteristics including cognitive function, mood, RBD, and freezing in patients with PD.

Chapter 16 - Essential tremor and the cerebellum

Essential tremor (ET) is a progressive and highly prevalent neurologic disease. Along with the tremors, mild to moderate gait ataxia and other signs of cerebellar dysfunction may occur (i.e., subtle saccadic eye movement abnormalities and abnormalities of motor timing) as well as cognitive features, some of which may be due to cerebellar dysfunction. Numerous neuroimaging studies indicate the presence of functional, metabolic, and structural abnormalities in the cerebellum of a patient with ET. In tandem with these clinical and imaging studies, which were gathering increasing support for the notion that the cerebellum and/or cerebellar systems seemed to be at the root of ET, a growing postmortem literature is for the first time beginning to identify microscopic abnormalities in the ET brain, most of which are centered on the Purkinje cells and connected neuronal populations, and are likely to be degenerative. In terms of treatment, most of these pharmacotherapeutic agents serve to enhance GABAergic neurotransmission, further bolstering the notion that ET may very well be a disorder with a primary Purkinje cell dysfunction resulting in reduced cerebellar cortical inhibition. Similarly, the interruption of presumably abnormal cerebellar outflow pathways to the thalamus is the mechanism of deep-brain stimulation surgery, which is highly effective in treating ET.

Fungal Cerebellar Abscess in an Immunocompetent Patient

Objective: We aimed to describe a case of fungal cerebellar abscesses due to Aspergillus in an immunocompetent patient. Methods: This was a case report of a patient who presented at King Abdulaziz University Hospital for management of fungal cerebellar abscess. Results: A 27-year-old Saudi patient presented with signs of cerebellar dysfunction, reduced visual acuity outcome, and hoarseness following medical therapy and neurosurgery for cerebellar aspergillosis. Brain computed tomography and magnetic resonance imaging scans revealed findings that were suggestive of a recurrent or residual abscess. Treatment was initiated with oral corticosteroids and liposomal amphotericin B. Two weeks later, liposomal amphotericin B was substituted for oral voriconazole. An initially planned surgical excision was deferred following the improvement of the patient’s symptoms. Conclusion: Fungal cerebellar abscesses due to Aspergillus are extremely rare, especially in immunocompetent patients. A high index of suspicion coupled with aggressive neurosurgical intervention and medical treatment can lead to a favorable outcome in patients with cerebellar abscesses due to Aspergillus.

A Missense Variant in KCNJ10 in Belgian Shepherd Dogs Affected by Spongy Degeneration with Cerebellar Ataxia (SDCA1).

Spongy degeneration with cerebellar ataxia (SDCA) is a severe neurodegenerative disease with monogenic autosomal recessive inheritance in Malinois dogs, one of the four varieties of the Belgian Shepherd breed. We performed a genetic investigation in six families and seven isolated cases of Malinois dogs with signs of cerebellar dysfunction. Linkage analysis revealed an unexpected genetic heterogeneity within the studied cases. The affected dogs from four families and one isolated case shared a ∼1.4 Mb common homozygous haplotype segment on chromosome 38. Whole genome sequence analysis of three affected and 140 control dogs revealed a missense variant in the KCNJ10 gene encoding a potassium channel (c.986T>C; p.Leu329Pro). Pathogenic variants in KCNJ10 were reported previously in humans, mice, and dogs with neurological phenotypes. Therefore, we consider KCNJ10:c.986T>C the most likely candidate causative variant for one subtype of SDCA in Malinois dogs, which we propose to term spongy degeneration with cerebellar ataxia 1 (SDCA1). However, our study also comprised samples from 12 Malinois dogs with cerebellar dysfunction which were not homozygous for this variant, suggesting a different genetic basis in these dogs. A retrospective detailed clinical and histopathological analysis revealed subtle neuropathological differences with respect to SDCA1-affected dogs. Thus, our study highlights the genetic and phenotypic complexity underlying cerebellar dysfunction in Malinois dogs and provides the basis for a genetic test to eradicate one specific neurodegenerative disease from the breeding population. These dogs represent an animal model for the human EAST syndrome.

Suspected Wilson's Disease Presenting with Normal Serum Ceruloplasmin Levels

Wilson’s disease, also known as ‘Hepatolenticular degeneration’ is a disorder of copper handling. The clinical picture parallels the pathophysiology with symptoms of basal ganglia (10 to 100%), cerebellar dysfunction (18 to 73%) and liver dysfunction (18 to 84%). The patient profile usually describes a young male or female with signs of cerebellar dysfunction (Ataxia, Dysarthria and Nystagmus), basal ganglia dysfunction (Choreoathetosis), Kayser Fleisher (KF) rings in cornea and hepatic involvement (any form of acute or chronic liver disease). The basic pathophysiology relates to improper handling of copper by the liver owing to the dysfunctional ATP7B gene. The diagnostic tests include an increased urinary copper excretion (100 ug/dl), reduced serum ceruloplasmin levels ( 200 ug/gm of liver tissue). Although reduced serum ceruloplasmin levels are observed in most patients of Wilson disease, some proportion of patients particularly with acute hepatitis type of presentation can spuriously have raised ceruloplasmin levels thus posing the clinicians a diagnostic challenge especially in rural resource limited set ups. Presentations like these can be quite misleading as clinical suspicion index remains pretty low despite extensive laboratory work up. We report a case of such a patient of acute hepatitis with normal serum ceruloplasmin levels but significantly elevated urinary copper excretion. The patient showed wonderful response to oral zinc replacement evidenced with clinicobiocemical improvement.

A Rare Case of Carcinoma Breast with Cerebellar Dysfunction Paraneoplastic Syndrome

Paraneoplastic Syndrome, as Paraneoplastic cerebellar degeneration (PCN), in carcinoma breast is a rare entity due to the autoimmune responses. We report a case report of 52 year female with carcinoma breast along with symptoms and signs of cerebellar dysfunction, which on further evaluation is found to be anti-YO autoantibody positive paraneoplastic syndrome. In spite of surgical and chemotherapy patient’s neurological condition worsened indicating the poor prognosis of the condition.

Cerebellar vermis hypoplasia in CHARGE syndrome: clinical and molecular characterization of 18 unrelated Korean patients.

CHARGE syndrome (OMIM 214800) is a rare autosomal-dominant congenital malformation syndrome that results from haploinsufficiency of the chromodomain helicase DNA-binding protein 7 (CHD7). We performed a phenotypic characterization and genetic analysis of CHD7 in 18 Korean patients with CHARGE syndrome. Eighteen unrelated Korean patients (10 females and 8 males; age range 0.0-19.6 years) with CHARGE syndrome were enrolled. Clinical data were collected by retrospective review of medical records. A serial analysis via sequencing and multiple ligation-dependent probe amplification of CHD7 was performed to determine the molecular genetic spectrum of the patients. The prevalence of cardinal symptoms was as follows: coloboma (13/18, 72.2%), heart defects (13/18, 72.2%), choanal atresia/stenosis (4/18, 22.2%), retarded growth (10/18, 55.6%), genital anomalies (15/18, 83.3%) and ear abnormalities (18/18, 100%). Five patients had cerebellar vermis hypoplasia (5/17, 29.4%) with no clinical symptoms or signs of cerebellar dysfunction. Furthermore, we identified genetic alterations in all 18 patients, including 10 novel mutations. Considering its frequency among patients with CHD7 mutations, cerebellar vermis hypoplasia may be a clinical diagnostic clue of CHARGE syndrome, although it is not included in the diagnostic criteria. And, the identification of CHD7 mutations may help the confirmative diagnosis.

7q11.23 Duplication syndrome: Physical characteristics and natural history.

In order to describe the physical characteristics, medical complications, and natural history of classic 7q11.23 duplication syndrome [hereafter Dup7 (MIM 609757)], reciprocal duplication of the region deleted in Williams syndrome [hereafter WS (MIM 194050)], we systematically evaluated 53 individuals aged 1.25-21.25 years and 11 affected adult relatives identified in cascade testing. In this series, 27% of probands with Dup7 had an affected parent. Seven of the 26 de novo duplications that were examined for inversions were inverted; in all seven cases one of the parents had the common inversion polymorphism of the WS region. We documented the craniofacial features of Dup7: brachycephaly, broad forehead, straight eyebrows, broad nasal tip, low insertion of the columella, short philtrum, thin upper lip, minor ear anomalies, and facial asymmetry. Approximately 30% of newborns and 50% of older children and adults had macrocephaly. Abnormalities were noted on neurological examination in 88.7% of children, while 81.6% of MRI studies showed structural abnormalities such as decreased cerebral white matter volume, cerebellar vermis hypoplasia, and ventriculomegaly. Signs of cerebellar dysfunction were found in 62.3%, hypotonia in 58.5%, Developmental Coordination Disorder in 74.2%, and Speech Sound Disorder in 82.6%. Behavior problems included anxiety disorders, ADHD, and oppositional disorders. Medical problems included seizures, 19%; growth hormone deficiency, 9.4%; patent ductus arteriosus, 15%; aortic dilation, 46.2%; chronic constipation, 66%; and structural renal anomalies, 18%. We compare these results to the WS phenotype and offer initial recommendations for medical evaluation and surveillance of individuals who have Dup7.

Long-term course of orthostatic tremor in serial posturographic measurement.

Primary orthostatic tremor (OT) is a rare neurological disease of unknown pathophysiology characterized by a high-frequency tremor mainly of the legs when standing. The aim of this study was to examine its long-term course by subjective estimation and objective recording by serial posturography and to obtain further standardized epidemiological and clinical data on patients with OT. A clinical cohort of 37 patients with the diagnosis of primary OT was screened for this longitudinal follow-up study. Eighteen patients consented to participate. During study visit all patients underwent a standardized neurological examination and completed subjective scales and scores. Posturographic recordings at follow-up were compared to prior clinical posturographic measurements in 15 cases. In our cohort the mean duration of symptoms was 14.1 ± 6.8 years. Subjectively, 78% of patients reported progression of the disease. Posturographic data (5.4 ± 4.0 years) revealed a significant increase of the total sway path (standing on firm ground with eyes open) from 2.4 ± 1.3 to 3.4 ± 1.4 m/min (p = 0.022) and of the total root mean square values from 9.8 ± 4.3 to 12.4 ± 4.8 mm (p = 0.028). None of these observations are explained by aging of the patients. Mean frequency of the tremor did not change over time (14.7 ± 1.9 Hz vs. 14.9 ± 2.0 Hz at follow-up). Clinically, most patients had signs of cerebellar dysfunction and a substantial portion also showed proprioceptive deficits in the long-term course. This long-term follow-up study indicates, that primary OT is a progressive disorder. Furthermore, the clinical observation of cerebellar dysfunction in most OT patients in the long-term course might indicate an important role of the cerebellum in its pathophysiology.

An Unusual Cause of Altered Mental Status in Elderly—Acute Cerebellitis: A Case Report and Review

Acute cerebellitis is a rare diagnosis found mostly in the pediatric population. The etiology, in most instances, is unknown. We describe the case of a 61-year-old woman who presented with acute mental status changes, signs of cerebellar dysfunction, and MRI findings of acute cerebellitis. A brief review of the existing literature and comparison of our case with previous reports are also presented.

Erdheim–Chester disease presenting with an intramedullary spinal cord lesion

Erdheim–Chester disease (ECD) is a rare form of nonLangerhans histiocytosis characterized by multi-systemic xanthogranulomatous infiltration. The disease commonly affects the skeleton, but may also involve the skin, viscera including the cardiovascular system and lungs, as well as the central nervous system [1–4]. Diagnosis is based on histopathology typically showing infiltration by histiocytes expressing CD68, but not CD1a [3]. In the nervous system, ECD commonly affects the neurohypophysis resulting in diabetes insipidus. Extrahypophyseal nervous system involvement is seen in about a third of ECD patients and includes intra-axial infiltrative lesions, meningioma-like masses, and periarterial infiltration [3, 5, 6]. Spinal cord involvement may occur due to extramedullary masses [3, 7, 8] but intra-axial cord lesions are rare and only a single patient has been described [9]. We report a case of ECD presenting with progressive spastic paraparesis caused by an intramedullary cord tumor. A 31-year-old female was referred to our clinic with a 10-year history of slowly progressive gait difficulties due to a spinal cord mass. She also complained of polydipsia, polyuria, and irregular menstruation. Clinical examination revealed spastic paraparesis with extensor plantar responses and normal sensory function. There was saccadic smooth pursuit in all directions and horizontal nystagmus on lateral gaze, but no other signs of cerebellar dysfunction. She had multiple periorbital xanthelasma-like lesions (Fig. 1). She did not complain of skeletal pain. MRI of the brain revealed symmetrical high T2 signal in the cerebellar white matter, sparing the dentate nuclei. There was calcification of the dentates and globus pallidus (Fig. 1). MRI of the spine showed diffuse, non-contrast enhancing, low T1 and T2 signal changes in multiple cervical and thoracic vertebrae. There was a fusiform masslesion of the thoracic cord showing inhomogeneously high T2 signal intensity and partial contrast enhancement (Fig. 2). Scintigraphy with technetium 99 and fluorodeoxyglucose positron-emission tomography (FDG-PET) showed pathological tracer uptake in the epiphyses of long bones, several cervical and thoracic vertebra (corresponding to signal changes on the MRI) and parts of the facial skeleton. Skeleton radiograms showed moderate hyperostosis of the skull and sclerotic changes in the epiphyses of the long bones (Fig. 1). A computed tomography (CT)-guided biopsy of the 9th thoracic vertebra was performed. Histology revealed a hypercellular bone marrow with focal fibrosis and infiltration C. Tzoulis (&) I. O. Gjerde Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway e-mail: chtzoulis@yahoo.com; charalampos.tzoulis@helsebergen.no

Ataxia-Telangiectasia Presenting With a Novel Immunodeficiency

Ataxia-telangiectasia is a rare autosomal recessive disorder characterized by progressive cerebellar ataxia, oculocutaneous telangiectasias, and variable degrees of immunodeficiency. Immunologic evaluations of affected patients often reveal anomalies of humoral and cell-mediated immunity. We describe a case of ataxia-telangiectasia with an atypical immunodeficiency and a novel mutation in the ATM gene. The patient presented at age 3 years with a perineal cellulitis associated with profound neutropenia and T-cell lymphopenia. Serum immunoglobulin levels and antibody titers were normal. Neurologic evaluation revealed minimal hypotonia and wide-based gait, without other signs of cerebellar dysfunction. The alpha-fetoprotein level was elevated, and molecular genetic testing confirmed the diagnosis of ataxia-telangiectasia, uncovering a novel ATM gene mutation c.3931C>T (p.Gln1311X) in exon 28. This patient presents a unique immunologic pattern with normal immunoglobulin levels, significant lymphopenia, and profound neutropenia. The diagnosis of ataxia-telangiectasia should be considered in children presenting with gait disorder and immunologic defects, regardless of subtype and severity.

Intracranial Hemorrhage Revealing Pseudohypoparathyroidism as a Cause of Fahr Syndrome

Pseudohypoparathyroidism is an infrequently encountered disease. It is one of the causes of Fahr syndrome which also is a rare clinical entity caused by multiple diseases. A 4-year-old man hospitalized for sudden onset left hemiparesis and hypertension was diagnosed to have right thalamic and midbrain hemorrhage on plain CT scan of the head which also revealed co-existent extensive intracranial calcifications involving the basal ganglia and cerebellum bilaterally. General physical examination revealed features of Albright hereditary osteodystrophy, goitre, hypertension, left hemiparesis, and signs of cerebellar dysfunction. Laboratory findings suggested hypocalcemia, hyperphosphatemia along with high TSH, low FT4, low FT3, and high anti-TPO antibody. Though bilateral intracranial calcifications are usually encountered as an incidental radiological finding in the CT scan of brain, in this case, the patient admitted for thalamic and midbrain hemorrhage was on investigation for associated intracranial calcification, and goitre was also found to have coexisting pseudohypoparathyroidism and autoimmune hypothyroidism.

Favorable response to rituximab in a patient with anti‐VGCC‐positive Lambert‐Eaton myasthenic syndrome and cerebellar dysfunction

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease that is characterized by impaired transmission across the neuromuscular junction due to autoantibodies directed against the presynaptic voltage-gated calcium channels (VGCC-ab). Clinical symptoms are usually characterized by proximal muscle weakness and mild dysautonomia. In some patients there are signs of cerebellar dysfunction as well, usually associated with cancer. Here we report the long-term follow-up of a patient with VGCC-ab-positive LEMS and a severe cerebellar syndrome but without evidence of cancer over 5 years. While conventional immunosuppressive therapy (steroids, azathioprine) failed, he improved with plasma exchange and consecutive treatment with rituximab. Muscle Nerve 40: 305-308, 2009.

Perverted head‐shaking and positional downbeat nystagmus in patients with multiple system atrophy

The diagnosis of multiple system atrophy (MSA) is mainly based on the clinical criteria, which are often of little assistance in the early stages of the disease. Positional downbeat nystagmus (pDBN) and perverted head-shaking nystagmus (pHSN), possible signs of cerebellar dysfunction, may be useful in differentiating MSA from other parkinsonian disorders. To investigate the occurrences of pDBN and pHSN in patients with MSA compared with those in patients with Parkinson's disease (PD). A total of 127 consecutive patients with MSA and 274 patients with PD underwent a video-oculographic recording of head-shaking and positional nystagmus over a year. The occurrences of pDBN and pHSN were higher in MSA than in PD. pDBN was more frequently observed in MSA with overt cerebellar signs than in those without, but the occurrence of pHSN did not differ between the MSA groups. pHSN was more frequently observed in MSA-p without overt cerebellar signs than in PD, but there was no difference in the occurrence of pDBN between them. The presence of pHSN and pDBN may be a clue for the diagnosis of MSA, and pHSN may be helpful in differentiating MSA-p from PD when the patients do not have overt cerebellar features.

Factor Analysis of Motor and Nonmotor Signs in Essential Tremor: Are These Signs All Part of the Same Underlying Pathogenic Process?

Essential tremor (ET) has traditionally been viewed as monosymptomatic. However, there is an emerging appreciation of an expanded number of motor manifestations as well as a new awareness of nonmotor manifestations. The current goal, through factor analyses, was to determine how these diverse signs relate to one another and shed light on their pathogenic bases. One hundred and thirty-eight ET patients had detailed neurological examinations. In these analyses, three separate factors emerged, explaining 58.7% of the variance. Factor I was comprised of the hallmark feature of ET, action tremor. It also included intention tremor, which is generally viewed as a sign of cerebellar dysfunction, and tremor duration. Factor II was comprised of cognitive test scores and age, and factor III, of rest tremor. Cognitive test scores did not fall into the same domain as motor features or tremor duration. These results suggest that: (1) the process that underlies cognitive dysfunction in ET is distinct from that which is responsible for action and intention tremors and their progression over time, and (2) cognitive dysfunction in ET is not likely due to cerebellar degeneration. Age loaded with cognitive test scores, further raising the possibility that age-related processes (e.g. Alzheimer-type changes) could underlie cognitive changes in ET.

Association of Familial Ataxia and Restless Legs Syndrome

Back to table of contents Previous article Next article LETTERFull AccessAssociation of Familial Ataxia and Restless Legs SyndromeEng-King Tan M.D.,Eng-King Tan M.D.Search for more papers by this author,Published Online:1 Apr 2007AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail SIR: Restless legs syndrome (RLS), characterized by an intense urge to move the lower extremities especially during the night, is associated with a number of medical conditions, such as uremia, iron deficiency, and neuropathy. RLS with a prevalence of 5% to 15%, is frequently underdiagnosed 1 – 3 and can be confused with anxiety states and other psychological syndromes, hyperthyroidism and drug-induced akathisia. Previous reports have highlighted an association between RLS and familial spinocerebellar ataxias (SCA) in German and Dutch patients. 2 – 5 However, the long-term association of these two conditions is unknown. The prevalence of RLS is much rarer among Asians, 6 and to our knowledge, RLS has not been reported in SCA patients in Asia. Here, we report an Asian patient with SCA who presented with restless legs symptoms that were initially attributed to stress and anxiety. We examined the relationship between RLS and SCA symptoms in this patient over a few years to highlight the need to recognize their coexistence early since RLS could be effectively treated.Case Report The patient of Asian origin presented with progressive unsteady gait and frequent falls. He had signs of cerebellar dysfunction, generalized hyperreflexia and lower limb spasticity, and was confirmed to have autosomal dominant SCA type 3 (SCA3), with an abnormal CAG trinucleotide repeat expansion. One year after the onset of his ataxia, he complained of an urge to move his lower extremities, particularly when at rest. This was preceded by an abnormal sensation in his toes and feet, which at times extended to his knees, described as “crawling,” “creeping,” and “itching.” He was troubled and anxious because the urge and sensation were often intense and distressing, and he had to move his legs and get up to walk to obtain relief. He was more aware of his symptoms during quiet time in the evening or night and when not distracted by other activities. He frequently woke up more than 10 times nightly because of sensation associated with restless legs and complained of poor sleep quality. His symptoms were initially attributed to his anxiety and depression and treatment for these symptoms was not effective. Subsequently, he was diagnosed with RLS based on the International Restless Legs Syndrome Study Group criteria. 5 After L -dopa was prescribed, his symptoms improved significantly. Investigations did not reveal a secondary cause for his RLS. Full blood count, urea/creatinine/electrolytes, and serum ferritin levels were normal. A nerve conduction test did not reveal any significant peripheral neuropathy. He was followed up over a 3-year period. His RLS symptoms appeared to progress with deterioration of his ataxia symptoms but could be controlled with L -dopa. His RLS symptoms would reemerge with withdrawal of the medication. CommentRLS was most likely related to the patient’s ataxia condition as the patient did not have any past or family history of RLS, his symptoms came only after the onset of his ataxia, and the clinical severity of both diseases appeared to move in tandem over a long period of time. Investigations did not reveal any evidence of anemia, renal failure, peripheral neuropathy, or arthritis, conditions which may predispose to RLS symptoms. Functional imaging studies have provided evidence implicating dopaminergic system impairment in RLS. Similarly, striato-nigral involvement has been demonstrated in neuropathological specimens of SCA3. Hence, it is possible that SCA3 and RLS may share a common pathophysiological mechanism. RLS and sensorimotor axonal neuropathy have been associated with intermediate CAG repeat size (53 and 54 repeats) in an SCA3 Dutch family. 5 Our RLS patient had an abnormal CAG repeat size (>60 repeats) and no neuropathy. Whether there is a correlation between the size of the CAG repeat expansion and the risk of RLS symptoms is not known. RLS symptoms can be confused with stress and anxiety in patients with familial SCA. The long-term follow-up of our patient supports the association of RLS and SCA reported in Caucasian patients. We need to recognize RLS early, even in Asian populations where RLS is apparently rare so that appropriate effective treatment can be instituted. Further studies into the pathophysiological link between RLS and SCA3 would be of academic interest.National Neuroscience Institute, SingHealth Research, Singapore

A case of isolated nodulus infarction presenting as a vestibular neuritis

We reported a patient with cerebellar infarction who presented with purely isolated vertigo, ipsilesional spontaneous nystagmus, and contralesional axial lateropulsion without usual symptoms or signs of cerebellar dysfunction. An MRI of the brain showed a small left cerebellar infarct selectively involving the nodulus. A pure vestibular syndrome in our patient may be explained by ipsilateral involvement of nodulo-vestibular inhibitory projection to vestibular nucleus. Clinicians should be aware of the possibility of a nodulus infarction in patient with acute vestibular syndrome, even if the pattern of nystagmus and lateropulsion is typical of a vestibular neuritis.