Metronidazole: A culprit to balance and speech

In a country like India, oral metronidazole is the commonly prescribed drug of choice for entities such as amebiasis and visceral abscesses. Oral such cases, it is usually well tolerated and safe but can cause serious neurological adverse events. Peripheral neuropathy commonly encounters in practice but central nervous system toxicity is also well documented as it crosses the blood–brain barrier easily. Neurological toxicity of metronidazole may be due to prolonged administration, high doses, or high cumulative doses. Magnetic resonance imaging (MRI) of brain is the modality of choice to evaluate brain involvement. In the brain, the splenium of the corpus callosum, dentate nucleus of the cerebellum, and posterior pons involvement are commonly seen and diagnostic. Here, we have an interesting case report of a patient who was on oral metronidazole treatment for his large liver abscess, presenting with a complaint of neurological symptoms of unsteady gait, vertigo, dysdiadochokinesia, and difficulty in speech. Moreover, thus suspected as metronidazole drug toxicity and further investigated for the same, and MRI typically shows cerebellar and posterior corpus callosal involvement

Magnetic resonance imaging features of cerebellar atrophy pattern after epilepsy / 中南大学学报(医学版)

OBJECTIVES@#Clinically, it has been found that some patients with epilepsy are accompanied by cerebellar atrophy that is inconsistent with symptoms, but the pattern of cerebellar atrophy after epilepsy and the role of cerebellar atrophy in the mechanism of epilepsy have not been elucidated. This study aims to explore the specific pattern of cerebellar atrophy after epilepsy via analyzing magnetic resonance images in patients with postepileptic cerebellar atrophy.@*METHODS@#A total of 41 patients with epilepsy, who received the treatment in Xiangya Hospital of Central South University from January 2017 to January 2022 and underwent cranial MRI examination, were selected as the case group. The results of cranial MRI examination of all patients showed cerebellar atrophy. In the same period, 41 cases of physical examination were selected as the control group. General clinical data and cranial MRI results of the 2 groups were collected. The maximum area and signal of dentate nucleus, the maximum width of the brachium pontis, the maximum anterior-posterior diameter of the pontine, and the maximum transverse area of the fourth ventricle were compared between the 2 groups. The indexes with difference were further subjected to logistic regression analysis to clarify the characteristic imaging changes in patients with cerebellar atrophy after epilepsy.@*RESULTS@#Compared with the control group, the maximum width of the brachium pontis and the maximum anterior-posterior diameter of the pontine were decreased significantly, the maximum transverse area of the fourth ventricle was increased significantly in the case group (all P<0.05). The difference in distribution of the low, equal, and high signal in dentate nucleus between the 2 groups was statistically significant (χ2=43.114, P<0.001), and the difference in the maximum area of dentate nucleus between the 2 groups was not significant (P>0.05). The maximum width of the brachium pontis [odds ratio (OR)=3.327, 95% CI 1.454 to 7.615, P=0.004] and the maximum transverse area of the fourth ventricle (OR=0.987, 95% CI 0.979 to 0.995, P=0.002) were independent factors that distinguished cerebellar atrophy after epilepsy from the normal control, while the anterior-posterior diameter of pontine (OR=1.456, 95% CI 0.906 to 2.339, P>0.05) was not an independent factor that distinguished them.@*CONCLUSIONS@#In MRI imaging, cerebellar atrophy after epilepsy is manifested as significant atrophy of the brachium pontis, significant enlargement of the fourth ventricle, and increased dentate nucleus signaling while insignificant dentate nucleus atrophy. This particular pattern may be associated with seizures and exacerbated pathological processes.

Unusual Involvement of Basal Ganglia and Dentate Nucleus in Children with Acute Encephalopathy with COVID-19

Children account for 1% to 5% of diagnosed COVID-19 infection with relatively mild presentation compared to adults. The frequency of neurological involvement in acute COVID-19 infection in children is unclear. COVID-19 is also considered to be a neurotropic virus, but so far, in the pediatric age group, very few cases with involvement of basal ganglia and no case of dentate nucleus involvement have been reported in the literature. The present paper reports two cases of acute encephalopathy with COVID-19, the frst case with basal ganglia involvement and the second with dentate nucleus involvement. Both cases required aggressive management and had complete neurological recovery on follow-up. Hence, these cases are reported to make everyone aware of the neurological presentation with atypical neuroimaging fnding of acute COVID-19 infection in the pediatric age group; timely management improves the outcome.

Cerebellar dentate nucleus and its veins on susceptibility weighted imaging / 解剖学报

Objective Make use of image dentate nucleus and the veins around it on susceptibility weighted images (SWI), explore the correlation between the location of hilum of dentate nucleus and the venous variation of dentate nucleus. Methods Selecting 51 healthy adults (24 men, 27 women) at the age between 18 and 30 years old to get the original images on 3. 0T MR. Process the original images by minimum intensity projections (mIP) observed and analyzed the morphology of dentate nucleus and veins around it on original and processed images. Results The length of dentate nucleus was (16. 64±0. 20)mm, and the width was (8. 36±0. 14)mm. There was no significant difference between bilateral dentate nucleus. The median angle of the long axis of the dentate nucleus was 26. 80° (interquartile distance was 34. 58°). The venous network of dentate nucleus was formed in 2 groups of veins: the lateral group, drained by the vein of the horizontal fissure and nuclear vein; the medial group, drained by vermian vein and central vein of dentate nucleus. These two groups had been further typing as follows: the lateral anterior group drained by the nuclear vein, finally opening to superior petrosal sinus; the lateral median group had plenty of small veins of lateral dentate nucleus converge into the vein of the horizontal fissure; the lateral posterior group drained by a lot of very small veins converging to vermian veins or medullary veins; the medial anterior group that the central vein of dentate nucleus and the paravermian vein were jointed at hilum of dentate nucleus, opening into straight sinus; the medial posterior group usually converged into tributaries of vermian vein, or converged with paravermian vein into tributaries of vermian vein. Totally 75. 49% of hilums of dentate nucleus were located at upper inner quadrant, the other 24. 51% of them were located at lower inner quadrant. Conclusion Dentate nucleus and its veins are clearly visible on the susceptibility weighted images, and the location of the hilum of dentate nucleus may be related to the abouchement of paravermian vein.

Metronidazole Induced Cerebellar Ataxia: A Rare Case Report

Introduction: Metronidazole is an antibiotic and anantiprotozoal drug very commonly used in our day to daypractice. It is either used alone or in combination with otherdrugs to treat Pelvic inflammatory disease, Endocarditis andBacterial Vaginosis. It is generally well tolerated and commonside effects include nausea, vomiting, abdominal cramps,metallic taste.Case report: We are presenting a rare case of Metronidazoleinduced cerebellar ataxia in a patient who received the drugfor a relatively shorter duration.Conclusion: The neurological features usually occurwhen the drug dose exceeds 2g/day for a prolonged period.Peripheral neuropathy, dizziness, encephalopathy, seizures,optic neuropathy can be seen. Cerebellar ataxia is a rare andserious side effect of this drug.

Magnetic resonance gadolinium-based contrast agent deposition in brain: Status and progress / 第二军医大学学报

Gadolinium-based contrast agents (GBCAs) are widely used in magnetic resonance imaging. Recently, a large amount of evidence indicates that change of magnetic resonance signal in deep brain nuclei is related to repeated injection of GBCAs. Especially in the dentatum and pallidum the gadolinium deposition is most obvious. This paper reviews the research status and policy progress of brain deposition of GBCAs, and introduces the relationship between gadolinium deposition in the brain and the type of GBCAs.

Increased signal intensity in the dentate nucleus on unenhanced T1-weighted MR images after multiple gadolinium-based contrast material administrations: a preliminary study / 中华放射学杂志

Objective To compare changes in signal intensity (SI) of the dentate nucleus (DN),pons and cerebrospinal fluid (CSF) on unenhanced T1-weighted magnetic resonance imaging (MRI) scans after multiple administrations of the linear gadolinium-based contrast agent.Methods Clinical and imaging data of forty-nine patients who underwent at least 4 consecutive enhanced MRI examinations were analyzed retrospectively (unenhanced T1-weighted MRI scans were performed before and after consecutive enhanced MRI examinations).The mean SI of DN,pons and CSF were measured on unenhanced T1-weighted images.The SI ratio of DN to pons was calculated by dividing the SI in the DN by that in the pans,and so was The DN to CSF SI ratio.The difference of SI ratio of DN-to-pons and DN-to-CSF in the same patient before and after repeated contrast-enhanced T1WI were analyzed by paired-samples t tests.Linear regression analysis was used to analyze whether the SI ratios of DN-to-pons,DN-to-CSF were correlated with any clinical factor.Results The SI ratios of DN-to-pons and DN-to-CSF after multiple contrast administrations were higher than those before enhancement,and the differences were statistically significant.The SI ratios of DN-to-pons and DN-to-CSF before and after repeated contrast enhancement were 0.98±0.62,1.05 ±0.54;3.89±0.94,4.97±1.61 (t=-8.494,-4.526,P＜0.001).The SI ratio differences showed a significant positive correlation with the number of previous gadolinium-based contrast material administrations (pons:b=0.006,P=0.003,CSF:b=0.144,P=0.009).There was no correlation with any other clinical factors(P＞0.05).Conclusions This study indicates that serial injections of linear gadolinium-based contrast agent may lead to an increase in SI in the DN.

Nuevo reparo anatómico para la identificación del núcleo dentado en el abordaje suboccipital / New anatomical repair for the identification of the tooth nucleus in the suboccipital approach

Introducción: El abordaje suboccipital constituye una de las vías de acceso más frecuentes a la fosa posterior. Objetivo: La finalidad del presente estudio es definir un reparo anatómico reproducible en la superficie suboccipital del cerebelo que permita ayudar a localizar el núcleo dentado (ND) del mismo. Material y Métodos: Quince cerebelos de adulto fueron estudiados, previa fijación con formol y congelación. Se realizaron cortes axiales y sagitales, con medición de las relaciones entre la fisura horizontal (FH) y el ND. Resultados: La proyección en profundidad de la FH permitió identificar el núcleo dentado en casi todos ellos. Conclusión: La identificación del ND en la cirugía a partir de la FH puede ser considerada un método rápido y confiable. Su utilización pre y perioperatoria podría disminuir las complicaciones derivadas de la lesión de dicho núcleo cerebeloso.

Introduction: The suboccipital approach is one of the most common surgical routes to the posterior fossa.Purpose: The aim of this study was to define a reproductible anatomic landmark in the suboccipital surface of the cerebellum, allowing to localize the dentate nucleus (DN).Material and methods: Fifteen cadaveric specimens (adult brains) were studied, previously fixed with formaldehyde and frozen. Sagittal and axial cuts were performed in the specimens, measuring the relationships between the horizontal fissure (HF) of the cerebellum and the DN.Results: The projection in depth of the HF allowed to identify the DN in almost all of them.Conclusion: The identification during surgery of the DN using the HF maybe a safe and quick method and its usage pre and intraoperatively can lower complications related to lesions of the DN.

A Case of Cerebellar Cognitive Affective Syndrome Exhibiting Paragraphia / The Japanese Journal of Rehabilitation Medicine

Paragraphia due to cerebellar cognitive affective syndrome (CCAS) has not been reported previously. This report presents a patient with cerebellar hemorrhage, showing cognitive dysfunctions including paragraphia. A 74-year-old right-handed man was hospitalized with sudden dizziness. CT demonstrated a small hemorrhage in the right cerebellar dentate nucleus. He also exhibited gait disturbance due to mild truncal ataxia and became aware of errors while writing his dairy. Neuropsychological assessments showed phonological paragraphia with Kana characters and semantic paragraphia with Kanji characters, as well as mild auditory comprehension and verbal memory disorders. Although MRI did not detect any abnormality in the cerebral hemispheres, SPECT demonstrated decreased cerebral blood flow in the left angular gyrus, frontal lobe and parieto-occipital lobe, predominantly on the left side. On neuropsychological assessment 3 months after stroke, the patient's paragraphia and auditory comprehension disorder had subsided, but his verbal memory disturbance remained. The clinical features in this case differed from those of CCAS cases previously reported. In particular, the lesion considered responsible for the cognitive dysfunctions in this case involved the right dentate nucleus, which is supplied by the superior cerebellar artery, but not the posterior inferior cerebellar artery, and especially the presence of dis-orders in writing ability, such as paragraphia. The possible mechanism of paragraphia in this case might be a reduction of cerebral blood flow in the angular gyrus due to a crossed cerebello-cerebral diaschisis. However, this case suggests that the right dentate nucleus contributes to the neuropsychological mechanism of writing.

Selective Neuronal Damage Produced by beta-fluoroethylacetate Intoxication in Rat Brain

Beta-fluoroethylacetate has been extensively used as the rodenticide in Korea. In some patients with acute poisoning, beta-fluoroethylacetate caused cerebellar dysfunction as a single and persistent neurologic sequela after a period of an acute neurological disorder which is characterized by mental deterioration, seizures, and respiratory failure. But there has been no report of pathological findings to explain neurological deficit. We tried to verify the histologic changes of the central nervous systems in beta-fluoroethylacetate poisoned rats. Silver staining(Gallyas) was used to evaluate the histology. In acute intoxication experiment with LD50(7mg/Kg), beta-fluoroethylacetate elicited acute onset of consciousness deterioration, generalized tonic-clonic seizures and large amplitude tremulous activity involving whole body with full recovery after 24 hours. There was no discernible pathologic change in CNS in acutely poisoned rats. However, when poisoned with sublethal dose(5mg/Kg) daily for five days, a moderate degree of nerve cell degeneration was found selectively in dentate nucleus, Purkinie cell layer, vestibulo-cochlear nucleus and striatum. This change was not seen in hippocampus, cerebral cortex or cerebellar cortex. These findings were well correlated with the previous reports of selective pathology in human 5-FU intoxication cases. Our preliminary results suggest that beta-fluoroethylacetate, a kind of cellular metabolism inhibitor may induce selective neuropathology mainly involving cerebellar output pathway in rats.

Electromyographical Changes of Anterior Tibial Muscle after Stimulation of Cerebella Dentate Nucleus in Cats

Through the use of stereotactic neurosurgical operation, some authors have employed chronic electrical stimulation of the dentate nucleus spasticity and each trial on spastic patients has show marked clinical improvement. We investigated the electrophysiological changes of cats after stereotactic electrical stimulation of the dentate nucleus to elucidate the possibility of clinical application and to evaluate the clinical results. The M-wave is an initial response and the F-wave is a late response in the electromyography of a muscle, which is stimulated by its original controlling nerve itself. There is evidence that the size of the F-wave is dependent on motor neuron excitability and its amplitude is increased significantly at spastic condition. If such a relationship exists, procedures which are carried out to relieve spasticity might be exerted to change the F-wave size and thus it might be possible to use the F-wave as an objective monitor during electrical stimulation of the dentate nucleus. We investigated this possibility in experiments on 10cats weighing between 2.7 Kg and 4.4 Kg. We studied the changes of M and F waves, recorded in EMG, after stereotactic stimulation to cerebellar dentate nucleus in cats. The results were as follows : 1) The change of mean value of M-wave amplitude was not significant(control group, 3591+/-1029 microV : stimulation group, 3424+/-927 microV, P>0.05). 2) The mean value of F-wave amplitude was significantly reduced about 56.7% after the dentate stimulation(control group, 443.2+/-119 microV : stimulation group, 251.3+/-99.4 microV, P<0.05). 3) The F/M ratio also significantly reduced, about 56.8% after the dentate stimulation(control group, 12.5+/-1.9%, stimulation group, 7.1+/-1.2%, P<0.05). Our experimental results demonstrated that the dentate stimulation markedly decreased the size of F-wave amplitude and F/M ration in the experimental cats and we concluded that these electrophysiological changes can be applied as a parameter of clinical evaluation of electrical dentate stimulation for the spasticity.