Case: 53-year-old Man with Ataxia

by Roy Strowd, MD

My Notes
  • Required.
Save Cancel
    Learning Material 2
    • PDF
      Slides Approach to Dysequilibrium Cerebellum.pdf
    • PDF
      Download Lecture Overview
    Report mistake

    00:01 Let's start with a case to understand why this information is important.

    00:05 This is a 53-year-old man with liver disease and recent hospitalization for osteomyelitis, who was placed on metronidazole and moxifloxacin for six weeks.

    00:17 The patient was recovering well until about two weeks ago, when he began to develop gait ataxia and dysarthria.

    00:23 So some cerebellar signs.

    00:26 This is slowly worsened to the point that he is having trouble walking.

    00:29 Exam shows truncal ataxia, difficulty with keeping himself upright dysarthric speech, saccadic overshoot on eye movement examination, so he's having trouble coordinating his eye movements.

    00:41 Otherwise, neurologic exam is unremarkable.

    00:44 MRI is performed and reveals T2-weighted hyperintense lesions in the bilateral deep cerebellar gray matter.

    00:52 So what's the most likely diagnosis? Well, as with other cases of the brain and cerebellum, the timeline of onset is important.

    01:00 This is a subacute onset condition.

    01:03 It's not acute like a stroke, or an intoxication or trauma, not chronic, like a degenerative cerebellar disease.

    01:09 This sounds like something more in the inflammatory, toxic, or metabolic category.

    01:16 The patient's description is that of cerebellar disequilibrium.

    01:20 There's prominent gait ataxia and imbalance, dysarthric of speech.

    01:24 And on examination, we find all of those cerebellar findings.

    01:28 So this isn't vertigo. It's not syncope, we're dealing with disequilibrium.

    01:34 And then importantly, for this case, are the imaging findings.

    01:37 We see edema or problems in the deep cerebellar nuclei, not in the hemispheres of the white matter, but in those deep cerebellar nuclei.

    01:46 So we're looking for a problem that has a predilection for the nuclei of the cerebellum.

    01:52 So what is the most likely diagnosis? Is this metronidazole-induced to cerebellar toxicity? Is this a post-infectious cerebellitis? Is this a cerebellar stroke? Or could this be hepatic encephalopathy? We don't like hepatic encephalopathy.

    02:08 In liver disease, which the patient has can cause hyperammonemia and hepatic encephalopathy.

    02:14 But that's an encephalopathy syndrome.

    02:17 Patients are confused and altered with varying degrees of sedation.

    02:21 This patient has no encephalopathy, and isolated cerebellar signs.

    02:26 So this is inconsistent with hepatic encephalopathy.

    02:30 This doesn't sound like a cerebellar stroke.

    02:32 Strokes again, are acute in onset, and this was more subacute in its onset.

    02:37 In addition, the MRI changes are very specific to the deep cerebellar gray matter nuclei.

    02:42 Their bilateral and symmetric.

    02:44 And typically we think of a stroke as being asymmetric on one side of the other, and often affecting the circumferential vessels as they course around the cerebellum and affecting the hemispheres and hemispheric function.

    02:58 Post infectious cerebellitis can be seen after an infection, but that's typically not something we see after an osteomyelitis.

    03:05 Typically, we see this after some type of viral infection.

    03:08 And importantly, post-infectious cerebellitis affects the hemispheres.

    03:13 Sometimes one or the other hemispheres, and sometimes bilaterally, but the hemispheres of the predominant area that are affected.

    03:20 And here we have a specific process that has a tropism or predilection for the deep gray matter of the cerebellum.

    03:28 And this is a typical case of metronidazole-induced cerebellar neurotoxicity.

    03:34 This is an uncommon condition, but we see it frequently.

    03:37 Metronidazole has a predilection for the dentate nucleus, and the deep gray matter structures.

    03:42 And so as neurologist, and when evaluating neurologic patients with neurologic disease, this is a condition we want to understand.

    03:50 Let's talk for a minute about Metronidazole-Associated Cerebellar Neurotoxicity.

    03:55 It's one of those conditions that reminds us of the importance for understanding, what those deep cerebellar nuclei are? This is a subacute onset cerebellar ataxia.

    04:05 That presents in patients who have been taking metronidazole.

    04:08 Often at moderate to high doses for a extended period of time.

    04:12 Patients present in a subacute fashion over several days to weeks, with primary ataxia.

    04:18 Both affecting the trunk, as well as appendicular function.

    04:22 And symptoms occurred during a prolonged course of metronidazole.

    04:27 Imaging is very specific and shows us the T2-weighted or FLAIR hyperintensity, as we saw in this case, that affects the bilateral dentate nuclei.

    04:35 Those are susceptible to this metronidazole induced toxicity.

    04:40 What's going on pathologically? Well we see edema or swelling within the dentate nuclei that caused this characteristic imaging finding.

    04:47 Typically this resolves with removal of the offending agent stopping the metronidazole, and in patients improve gradually, over the next several weeks and sometimes months.

    04:57 Many returning back to normal function.

    About the Lecture

    The lecture Case: 53-year-old Man with Ataxia by Roy Strowd, MD is from the course Vertigo, Dizziness, and Disorders of Balance.

    Included Quiz Questions

    1. MRI showing edema in the deep cerebellar gray matter
    2. MRI showing diffuse cerebellar degeneration
    3. Recent history of osteomyelitis
    4. Very sudden symptom onset
    5. A short course of low-dose metronidazole
    1. The dentate nuclei are impacted by this disease.
    2. A T1-weighted MRI is usually ordered for diagnosis.
    3. Disease development is unrelated to metronidazole dosage.
    4. Metronidazole-induced cerebellar toxicity is a progressive disease with a poor prognosis.
    5. The lateral hemispheres are the first to be impacted.

    Author of lecture Case: 53-year-old Man with Ataxia

     Roy Strowd, MD

    Roy Strowd, MD

    Customer reviews

    5,0 of 5 stars
    5 Stars
    4 Stars
    3 Stars
    2 Stars
    1  Star