Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion in an Adult with Cerebellar Ataxia: A Case Report.

Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is a clinicoradiological syndrome characterized by transient mild encephalopathy and magnetic resonance imaging (MRI) findings of a reversible lesion in the splenium of the corpus callosum (SCC). Patients with MERS generally present with central nervous system symptoms such as consciousness disturbance, headache, and seizure; adult-onset MERS with cerebellar ataxia is rare. A 53-year-old man was admitted to our hospital with fever of 1 week's duration, headache, neck stiffness, and gait disturbance. Neurological examination revealed bilateral intention tremor (predominantly affecting the right hand) and gait ataxia. Diffusion-weighted brain MRI showed a focal hyperintense lesion in the SCC. Cerebrospinal fluid analysis revealed elevated levels of mononuclear cells and proteins. Brain imaging with 123I-iofetamine single-photon emission computed tomography showed reduced cerebral blood flow in the left thalamus and right cerebellum. Several diseases, including cerebellar stroke and acute cerebellitis, develop as comorbidities in patients with acute cerebellar ataxia. This case suggests that MERS should be suspected in adults with cerebellar ataxia.

Movement disorder in a patient with Human Immunodeficiency Virus on an anti-retroviral therapy: A Case Report.

Human Immunodeficiency Virus associated neurocognitive dysfunction can present as a case of movement disorder in a patient with prolonged antiretroviral therapy. Diagnosis was made after ruling out space occupying lesions, nutritional deficiencies and infectious causes through brain imaging and cerebrospinal fluid analysis. With multidisciplinary care and change of antiretroviral therapy to drugs with higher cerebrospinal fluid penetration, symptoms of the patient improved over a span of six months. Delayed neurological damage due to Human Immunodeficiency Virus can present with isolated cerebellar symptoms.

Neurologic Deficits in Patients With Newly Diagnosed Celiac Disease Are Frequent and Linked With Autoimmunity to Transglutaminase 6.

BACKGROUND & AIMS: Celiac disease is an autoimmune disorder induced by ingestion of gluten that affects 1% of the population and is characterized by gastrointestinal symptoms, weight loss, and anemia. We evaluated the presence of neurologic deficits and investigated whether the presence of antibodies to Transglutaminase 6 (TG6) increases the risk of neurologic defects in patients with a new diagnosis of celiac disease. METHODS: We performed a prospective cohort study at a secondary-care gastroenterology center of 100 consecutive patients who received a new diagnosis of celiac disease based on gastroscopy and duodenal biopsy. We collected data on neurologic history, and patients were evaluated in a clinical examination along with magnetic resonance imaging of the brain, magnetic resonance (MR) spectroscopy of the cerebellum, and measurements of antibodies against TG6 in serum samples. The first 52 patients recruited underwent repeat MR spectroscopy at 1 year after a gluten-free diet (GFD). The primary aim was to establish if detection of antibodies against TG6 can be used to identify patients with celiac disease and neurologic dysfunction. RESULTS: Gait instability was reported in 24% of the patients, persisting sensory symptoms in 12%, and frequent headaches in 42%. Gait ataxia was found in 29% of patients, nystagmus in 11%, and distal sensory loss in 10%. Sixty percent of patients had abnormal results from magnetic resonance imaging, 47% had abnormal results from MR spectroscopy of the cerebellum, and 25% had brain white matter lesions beyond that expected for their age group. Antibodies against TG6 were detected in serum samples from 40% of patients-these patients had significant atrophy of subcortical brain regions compared with patients without TG6 autoantibodies. In patients with abnormal results from MR spectroscopy of the cerebellum, those on the GFD had improvements detected in the repeat MR spectroscopy 1 year later. CONCLUSIONS: In a prospective cohort study of patients with a new diagnosis of celiac disease at a gastroenterology clinic, neurologic deficits were common and 40% had circulating antibodies against TG6. We observed a significant reduction in volume of specific brain regions in patients with TG6 autoantibodies, providing evidence for a link between autoimmunity to TG6 and brain atrophy in patients with celiac disease. There is a need for early diagnosis, increased awareness of the neurologic manifestations among clinicians, and reinforcement of adherence to a strict GFD by patients to avoid permanent neurologic disability.

Pseudo-ataxia due to Osteoid Osteoma.

Background: Ataxia is diagnosed by typical features on examination suggestive of a cerebellar etiology and can invoke extensive diagnostic testing. Osteoid osteomas (OOs) are benign bone tumors of the lower limbs that occasionally present with focal neurological signs. Case Report: A 3-year-old male presented with apparent progressive gait ataxia and non-specific leg pain. Initial imaging was unremarkable. However, 12 months later, a lesion was identified in the distal right femur, which was found to be an OO. The gait disorder and pain resolved after surgery. Discussion: This case highlights the challenges of diagnosing a gait disorder in young children.

CLIPPERS and the need for long-term immunosuppression.

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS) is a rare chronic inflammatory disorder of the central nervous system. Herein, we describe the case of a 62-year-old female who presented with right sided facial tingling, gait ataxia and diplopia. Neuroimaging revealed pontine curvilinear enhancing lesions with extension into cerebellar peduncles, characteristic of CLIPPERS. This report discusses the differential diagnosis and the importance of prolonged immunomodulatory treatment for this rare neuro-inflammatory disorder. Long-term immunosuppression appears to be mandatory in order to achieve sustained remission and prevent disability related to atrophy of the structures involved in repeated attacks.

Progressive gait ataxia following deep brain stimulation for essential tremor: adverse effect or lack of efficacy?

Thalamic deep brain stimulation is a mainstay treatment for severe and drug-refractory essential tremor, but postoperative management may be complicated in some patients by a progressive cerebellar syndrome including gait ataxia, dysmetria, worsening of intention tremor and dysarthria. Typically, this syndrome manifests several months after an initially effective therapy and necessitates frequent adjustments in stimulation parameters. There is an ongoing debate as to whether progressive ataxia reflects a delayed therapeutic failure due to disease progression or an adverse effect related to repeated increases of stimulation intensity. In this study we used a multimodal approach comparing clinical stimulation responses, modelling of volume of tissue activated and metabolic brain maps in essential tremor patients with and without progressive ataxia to disentangle a disease-related from a stimulation-induced aetiology. Ten subjects with stable and effective bilateral thalamic stimulation were stratified according to the presence (five subjects) of severe chronic-progressive gait ataxia. We quantified stimulated brain areas and identified the stimulation-induced brain metabolic changes by multiple 18 F-fluorodeoxyglucose positron emission tomography performed with and without active neurostimulation. Three days after deactivating thalamic stimulation and following an initial rebound of symptom severity, gait ataxia had dramatically improved in all affected patients, while tremor had worsened to the presurgical severity, thus indicating a stimulation rather than disease-related phenomenon. Models of the volume of tissue activated revealed a more ventrocaudal stimulation in the (sub)thalamic area of patients with progressive gait ataxia. Metabolic maps of both patient groups differed by an increased glucose uptake in the cerebellar nodule of patients with gait ataxia. Our data suggest that chronic progressive gait ataxia in essential tremor is a reversible cerebellar syndrome caused by a maladaptive response to neurostimulation of the (sub)thalamic area. The metabolic signature of progressive gait ataxia is an activation of the cerebellar nodule, which may be caused by inadvertent current spread and antidromic stimulation of a cerebellar outflow pathway originating in the vermis. An anatomical candidate could be the ascending limb of the uncinate tract in the subthalamic area. Adjustments in programming and precise placement of the electrode may prevent this adverse effect and help fine-tuning deep brain stimulation to ameliorate tremor without negative cerebellar signs.

Paroxysmal dysarthria and ataxia after midbrain infarction.

The authors describe a patient who showed paroxysmal dysarthria and right-limb ataxia after midbrain infarction. SPECT imaging showed marked hypoperfusion in the left parietal lobe while the patient was having frequent paroxysmal attacks. After treatment with phenytoin, the symptoms and hypoperfusion in SPECT imaging improved. The authors conclude that dysfunction of the cerebellothalamocortical pathway after midbrain infarction may cause paroxysmal dysarthria and ataxia.

Detection of acute Epstein Barr virus cerebellitis using sequential brain HMPAO-SPECT imaging.

We used Technetium-99m hexamethyl propylene amine oxime single-photon emission computed tomography (HMPAO-SPECT) and magnetic resonance imaging (MRI) to evaluate a 30-year-old woman who developed cerebellar dysfunction after infection with Epstein Barr virus. Although no abnormal findings were evident from a brain MRI, the HMPAO-SPECT revealed increased perfusion in both cerebellar hemispheres. The patient improved without specific treatment. Two sequential HMPAO-SPECTs showed gradually reduced hyperperfusion in the cerebellum, which was correlated with her clinical recovery. We suggest that brain HMPAO-SPECT may thus be useful for identifying acute cerebellitis and predicting its clinical outcome.

Cerebellar activation during ataxic gait in olivopontocerebellar atrophy: a PET study.

OBJECTIVE: To investigate the possible abnormal regional brain metabolism during ataxic gait in olivopontocerebellar atrophy (OPCA), and to evaluate the response of the cerebellar subregions to instability during bipedal gait. MATERIAL AND METHODS: On 9 patients with OPCA in early phase and on 10 age-matched normal subjects, we performed positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) under two different conditions: supine resting and 30 min treadmill walking. RESULTS: Both in normals and in patients with OPCA, the FDG uptake in the walking state (Uwalk) was significantly greater than that in the resting state (Urest) in the pyramis, declive-folium-tuber and culmen of the cerebellar vermis, and in the thalamus. In the patients, the Uwalk was also significantly greater than the Urest in the posterior lobe of cerebellar hemisphere and in the pons and midbrain. In the pyramis, the activation ratio (= Uwalk/Urest) of the patients was significantly lower than that of the normals. CONCLUSIONS: We considered that these findings reflect the pathophysiology of ataxic gait in OPCA patients and the compensatory mechanism for the instability during ataxic gait.