[Transient changes in food preference in a patient with cerebellar infarction].

A 44-year-old woman was admitted to our hospital due to dizziness and ataxia of the trunk and right upper limb. Brain MRI revealed an acute infarct lesion in the right posterior inferior cerebellar artery territory. In addition to the cognitive deterioration observed in the subacute phase, a change was noted in her food preference-from light-tasting, low-caloric Japanese cuisine, sugarless coffee, and hot drinks to strong-tasting, high-caloric Western cuisine, sugar-rich coffee, and iced drinks. Single-photon emission computed tomography showed hypoperfusion in the bilateral frontal lobes and right cerebellum. These cognitive and food preference-related changes were gradually restored over six months after the onset. The reduced cerebral blood flow in the bilateral frontal lobes also restored along with the clinical improvement, with the maximal changes in the bilateral subcallosal areas. This case suggests that changes in food preference can occur as a symptom of cerebellar infarction, possibly by the mechanism similar to cerebellar cognitive affective syndrome.

Proton pump inhibitors and symptomatic hypomagnesemic hypoparathyroidism.

Hypomagnesemia is a common but often overlooked problem in hospitalized patients. Unrecognized hypomagnesemia can cause serious complications. The association of hypokalemia and hypocalcemia is strongly evocative of a magnesium deficiency. Research into the causes of hypomagnesemia is imperative, as it will definitely change the approach, treatment and prognosis. We report the case of a 65-year-old man with chronic hypocalcemia and hypokalemia associated with cerebellar syndrome, a solitary seizure and cerebellar hyperintensities on magnetic resonance imaging. After the detection and treatment of hypomagnesemia with oral supplements of magnesium and the replacement of pantoprazole with ranitidine, we observed immediate relief of the symptoms. In conclusion, in clinical practice, magnesium depletion should be investigated in elderly patients with hypocalcemia treated with proton pump inhibitors for many years, in particular in the presence of neurological disorders.

Targeting the red nucleus for cerebellar tremor.

Deep brain stimulation of the thalamus (and especially the ventral intermediate nucleus) does not significantly improve a drug-resistant, disabling cerebellar tremor. The dentato-rubro-olivary tract (Guillain-Mollaret triangle, including the red nucleus) is a subcortical loop that is critically involved in tremor genesis. We report the case of a 48-year-old female patient presenting with generalized cerebellar tremor caused by alcohol-related cerebellar degeneration. Resistance to pharmacological treatment and the severity of the symptoms prompted us to investigate the effects of bilateral deep brain stimulation of the red nucleus. Intra-operative microrecordings of the red nucleus revealed intense, irregular, tonic background activity but no rhythmic components that were synchronous with upper limb tremor. The postural component of the cerebellar tremor disappeared during insertion of the macro-electrodes and for a few minutes after stimulation, with no changes in the intentional (kinetic) component. Stimulation per se did not reduce postural or intentional tremor and was associated with dysautonomic symptoms (the voltage threshold for which was inversed related to the stimulation frequency). Our observations suggest that the red nucleus is (1) an important centre for the genesis of cerebellar tremor and thus (2) a possible target for drug-refractory tremor. Future research must determine how neuromodulation of the red nucleus can best be implemented in patients with cerebellar degeneration.

Stuttering after right cerebellar infarction: a case study.

UNLABELLED: We report a male patient with neurogenic stuttering after cerebellar infarction. He had suffered from frontal and thalamus damage and he had exhibited aphasia, but his speech had been fluent until onset of the cerebellar infarction. Results of analysis of speech samples included the following: (1) the patient showed very frequent syllable repetition and part-word repetition. (2) The stuttering occurrence rate at the second test was much higher than at the first test. (3) Almost all stuttering occurred on initial word sounds; stuttering on the medial and final word was less frequent. (4) Adaptation effect was absent. (5) Secondary behaviors such as closing of the eyes and grimacing were observed. The internal model related to cerebellar functions can be modified using feedback-error information. Results suggest that internal model dysfunction caused this patient's stuttering. EDUCATIONAL OBJECTIVES: After reading this text, the reader will be able to: (1) provide characteristics of neurogenic stuttering after the cerebellum infarction; (2) discuss the relationship between neurogenic stuttering and functions of the cerebellum.

Cerebellar cortical degeneration in cattle caused by Solanum kwebense.

The pathology of maldronksiekte, a sporadic neurological disorder of cattle caused by the ingestion of the plant Solanum kwebense in certain parts of South Africa, was studied in three chronic field cases. There was loss of cerebellar Purkinje cells with the remaining neurons either swollen or shrunken and showing degeneration and necrosis. Ultrastructurally, neurons with a swollen perikaryon showed depletion and empty dilated cisternae of granular endoplasmic reticulum. In a few Purkinje cells, the cytoplasm contained small numbers of lamellar and membranous bodies. In the shrunken neurons, the highly condensed cytoplasm contained distended Golgi saccules, dense clusters of granular endoplasmic reticulum and swollen mitochondria. Lectin histochemistry revealed that the cytoplasmic vacuoles in some distended Purkinje cells stained strongly with Canavalia ensiformis (ConA) agglutinin and weakly with Triticum vulgaris (WGA) and succinyl-WGA (S-WGA) agglutinin. The pattern of lectin binding only partially agreed with that reported in calves poisoned with Solanum fastigiatum, causing a presumed glycolipid storage disease. Apoptosis was not detected in neurons using a commercial deoxyuridine triphosphate nick-end labelling (TUNEL) method. The pathogenesis of the cerebellar lesions is unknown but the intoxication may have resulted from the inability of neurons, in particular Purkinje cells, to metabolise a plant toxin or cellular substrate.

Eyeblink conditioning anomalies in bipolar disorder suggest cerebellar dysfunction.

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.

State estimation in the cerebellum.

An exciting hypothesis about the cerebellum is that its role is one of state estimation--a process that combines efferent copies of motor commands with afferent sensory signals to produce a representation of the current status of the peripheral motor system. Sensory inputs alone cannot provide a perfect state signal because of inevitable delays in their afferent pathways. We have recently reported the effects of transcranial magnetic stimulation (TMS) over the ipsilateral cerebellum as healthy subjects made rapid reaching movements towards visually defined targets (Miall et al. in PLoS Biology 5:2733-2744, 2007). Errors in the initial direction and in the final finger position of this reach-to-target movement were consistent with the reaching movements being planned and initiated from an estimated hand position that was about 138 ms out of date. This interval is consistent with estimates of the delays in sensory motor pathways that would inform the central nervous system of the peripheral status. We now report new data using the same paradigm, testing the effects of varying the TMS stimulus train from one, two, or three pulses. We show that the errors in movement are relatively insensitive to the TMS pulse-train duration. The estimated time interval by which the hand position is mislocalized varied by only 12 ms as the TMS train duration increased by 100 ms. Thus, this interval is likely to reflect physiological processes within the cerebellum rather than the TMS-stimulus duration. This new evidence supports our earlier claim that the cerebellum is responsible for predictively updating a central state estimate over an interval of about 120-140 ms. Dysfunction of the cerebellum, whether through disease or experimental procedures, leads to motor errors consistent with a loss of knowledge of the true state of the motor system.

Deep brain reversible encephalopathy: association with secondary antiphospholipid antibody syndrome.

We present a case of a patient with systemic lupus erythematosus and secondary antiphospholipid syndrome. The patient presented with acute right cerebellar infarction and clinical and imaging evidence of brain stem and bilateral thalamic encephalopathy that resolved completely.

Diagnostic value of vestibular evoked myogenic potentials in cerebellar and lower-brainstem strokes.

BACKGROUND: Vestibular evoked myogenic potentials (VEMPs) provide assessment of vestibular function. They consist in picking up compound muscle action potentials in the sternocleidomastoid (SCM) muscles in response to auditory stimulation of the vestibulum. VEMP testing has found application mainly in peripheral vestibular disorders, whereas reports about VEMPs in central vestibular lesions are rather scarce. AIMS OF THE STUDY: Based on the physiological connections between the cerebellum and the vestibular nuclei, we investigated the influence on VEMPs of cerebellar and lower-brainstem strokes. We examined whether or not this method may be suitable as a clinical tool for the evaluation of the extent of cerebellar strokes. PATIENTS AND METHODS: Nineteen patients with cerebellar ischemic stroke and 15 patients with lower-brainstem ischemic stroke (11 in the pons, four in the medulla) were included. The latencies and amplitudes of P13 and N23 in both groups of patients were compared with those obtained in a control group of 53 normal individuals. RESULTS: VEMP responses were obtained in all patients and controls. At the group level, mean peak latencies and amplitudes, and the number of subjects with significantly deviant values did not differ between patients and controls. There were no latency or amplitude differences ipsilaterally or contralaterally to the lesion. At the individual level, there was no correlation between laterality of lesion and that of P13 or N23 abnormalities in patients with cerebellar strokes; however, there were two patients (one pontine, one medullar stroke) who presented P13 and N23 latency abnormalities ipsilaterally to the lesion. CONCLUSION: Cerebellar strokes do not influence VEMPs. Moreover, despite previous reports, we were unable to find at a group level any statistically significant VEMP changes in patients with lower-brainstem strokes as compared with controls. Therefore, VEMPs do not appear a suitable tool for assessment of brainstem integrity in patients with posterior fossa strokes. However, they could constitute a sensitive method for documentation of involvement of the central vestibular pathways in patients with brainstem stroke.

Cerebellar symptoms heralding bilirubin encephalopathy in Crigler-Najjar syndrome.

Children with Crigler-Najjar syndrome type I are at increased risk for neurologic deficits. Cerebellar symptoms are not prominent and appear in adolescent or adult patients with this syndrome. We report a 2-year-old female with Crigler-Najjar syndrome type I who presented severe cerebellar symptoms revealing bilirubin encephalopathy. The patient improved slowly with the duration of phototherapy. Cerebellar symptoms can be the initial manifestation of kernicterus in children with Crigler-Najjar syndrome type I.

Posterior fossa ischemia and bilateral vertebral artery hypoplasia.

OBJECTIVE: To discuss cerebellar infarct in a patient with bilateral hypoplasia of the vertebral arteries. CLINICAL FEATURES: A 67-year-old woman suffered neck pain and headaches immediately after a minor motor vehicle accident. Fracture and dislocation were radiographically ruled out. Within a few days, the patient began to experience symptoms of vertigo and dizziness. Computed tomography scanning of the brain revealed a cerebellar infarct, and an angiogram of the vertebral arteries demonstrated bilateral hypoplasia. INTERVENTION AND OUTCOME: The cerebellar infarct created mild, stable symptoms, and the patient was monitored closely in a hospital setting until the risk of possible complications was negligible. After an uncomplicated and full recovery, the patient was given recommendations regarding critical neck positions to decrease the potential for further ischemic events. CONCLUSION: Cerebellar infarcts are rare and may be associated with rare vascular anomalies.

Hyperbaric chamber-related decompression illness in a patient with asymptomatic pulmonary sarcoidosis.

An asymptomatic 46-yr-old male sustained an acute neurologic insult, appearing during the decompression phase of a 50-m dry hyperbaric chamber dive. The right hemisyndrome was most probably related to diving, since symptoms responded rapidly to the early commenced recompression therapy. Further diagnostics revealed a previously unknown pulmonary sarcoidosis with bilateral pulmonary opacities and pleural adhesions that might have predisposed to arterial gas embolism secondary to pulmonary barotrauma. This case may illustrate a potential risk of decompression illness even during dry chamber dives in patients suffering from asymptomatic pleuro-parenchymal pulmonary disease. The value of chest X-ray in the medical assessment of fitness to dive is therefore emphasized.

Clinical and stabilometric monitoring in a case of cerebellar atrophy with vitamin E deficiency.

The authors describe a case of early onset ataxia with cerebellar atrophy and vitamin E deficiency, treated with alpha-tocopherol supplementation and physically rehabilitated by postural biofeedback. Clinical assessments, serum vitamin E levels and postural evaluation by means of a stabilometric platform continued for about 2 years and significant clinical improvement was recorded. Our study confirms that combined physical therapy and vitamin E supplementation may result in improvement of cerebellar function. Motor improvement is directly related to vitamin E serum levels, providing further confirmation that normal vitamin E levels are crucial for proper brain functions.

HMPAO single-photon emission computed tomography in posterior circulation infarcts.

The sensitivity of single-photon emission computed tomography (SPECT) in evaluating posterior circulation infarcts compared with that of computed tomography (CT) or magnetic resonance imaging (MRI) remains unknown. In a hospital-based population, the authors studied SPECT, CT, and MRI in 35 consecutive patients presenting with acute infarction clinically localized in the thalamus (7), posterior cerebral artery (PCA) territory (15), brainstem (19), and cerebellum (3). Multiple infarcts were noted in 8 patients. Overall, the SPECT sensitivity was lower than that of MRI (21% vs 93%, p = 0.004) and CT (42% vs 65%, p = 0.046). The SPECT and CT sensitivities were not significantly different (67% vs 73%) for PCA infarcts. Performed within 24 hours, SPECT showed a relevant hypoperfusion in all PCA infarcts. For brainstem infarcts, CT (33%, p = 0.074) and MRI (91%, p = 0.004) were more sensitive than SPECT, which showed no hemispheric hypoperfusion. The sensitivity of the three imaging techniques was 100% for large cerebellar infarcts. For the small group of thalamic infarcts, the SPECT, CT, and MRI sensitivities were 14, 71, and 100%, respectively. Thus, SPECT compared to CT and MRI is not helpful in the subacute phase to localize PCA and cerebellar infarcts and is of limited value for thalamic infarcts. In the first hours, the absence of cerebral hypoperfusion in brainstem infarcts may help to differentiate them from hemispheric infarcts usually associated with profound hypoperfusion.

Vertigo as manifestation of vertebral artery dissection after chiropractic neck manipulations.

We recently observed a case of vertebral artery (VA) dissection following chiropractic neck manipulations. The first manifestation was unusual; in the form of vertigo. Therefore, the patient was referred to the otoneurologist. A VA dissection should be suspected in a case of vertigo following chiropractic neck manipulations, and vestibular tests should be done carefully, avoiding Rose's positions. In our case, the diagnosis was based on Doppler sonography and angiography. Chiropractic neck manipulations are the most frequent cause of traumatic VA dissection. Practitioners should be aware that, in some cases, these manoeuvres are life threatening.