TerelNewton.com - = neurologic

Most Likely Diagnoses

Cervical spondylotic myelopathy (CSM) — The ventral cord distortion at C5-6 and C6-7 is the most immediately actionable finding. CSM can cause gait and balance disturbances, and upper-motor-neuron signs including spasticity and hyperreflexia. However, CSM alone would not typically explain dysarthria, which localizes above the cervical cord (brainstem, cerebellum, or cortex). This makes CSM an incomplete explanation for the full presentation.

[1]

Diabetic sensory ataxia / peripheral neuropathy — Diabetes can cause severe proprioceptive loss leading to sensory ataxia with gait imbalance. This would be supported by a positive Romberg sign, impaired vibration/position sense, and absent ankle reflexes. However, like CSM, this does not explain speech involvement.

[2]

Nutritional/metabolic deficiency — Vitamin B12, thiamine (B1), vitamin E, and copper deficiency can cause a combined picture of myelopathy, neuropathy, cerebellar ataxia, and dysarthria. Diabetic patients on metformin are at particular risk for B12 deficiency. This is a treatable and must-not-miss diagnosis.

[3-4]

Autoimmune/inflammatory cerebellar ataxia — Gluten ataxia (anti-tissue transglutaminase antibodies), anti-GAD65 ataxia, and paraneoplastic cerebellar degeneration can present with cerebellar ataxia and dysarthria with a normal or near-normal brain MRI early in the course.

[3-4]

Hereditary spinocerebellar ataxia (SCA) — Slowly progressive ataxia with dysarthria in a 38-year-old should raise consideration for genetic ataxias (SCA types 1, 2, 3, 6, 7; Friedreich ataxia). Cervical cord atrophy has been described in SCA1 and Friedreich ataxia.

[5-6]

Important Not to Miss

Posterior circulation ischemic stroke/TIA — Dysarthria and ataxia are classic posterior circulation symptoms. A normal brain MRI does not fully exclude this, particularly for small brainstem infarcts; DWI can occasionally be negative. If onset was acute/subacute, vascular imaging (CTA or MRA of head and neck) is warranted.

[7-9]

CNS demyelinating disease (multiple sclerosis, NMO) — Can present with myelopathy and cerebellar signs. A normal brain MRI makes this less likely but does not exclude spinal cord demyelination; the cervical MRI findings should be scrutinized for signal abnormality within the cord itself.

Recommended Next Steps

Assuming the presentation is subacute-to-chronic and the patient is hemodynamically stable:

Targeted history — Clarify the tempo of onset (acute vs. progressive over weeks-months), alcohol use, medication history (especially metformin), dietary habits, family history of ataxia, and any associated symptoms (numbness, urinary dysfunction, weight loss, chronic cough).

Focused exam — Distinguish sensory from cerebellar ataxia at the bedside: Romberg sign, vibration/proprioception testing, finger-nose with eyes open vs. closed, rapid alternating movements, nystagmus assessment, and upper-motor-neuron signs (Hoffmann, Babinski, clonus, hyperreflexia) to assess for myelopathy.

[1-2][10]

Initial workup:

Labs: CBC, CMP, vitamin B12 (with methylmalonic acid), folate, vitamin E, thiamine, copper, ceruloplasmin, TSH, HbA1c, ESR/CRP, RPR/VDRL, HIV, tissue transglutaminase IgA, anti-GAD65 antibodies

[3-4][11]

Nerve conduction studies/EMG to characterize any peripheral neuropathy and differentiate sensory from cerebellar ataxia

[6][10]

Vascular imaging (CTA or MRA of head and neck) if any concern for acute/subacute onset to evaluate posterior circulation

[8-9]

Review cervical MRI carefully for intramedullary signal change (T2 hyperintensity) suggesting myelopathy vs. simple disc bulge without cord signal change

Red flags for escalation: Acute onset, rapid progression over days-weeks, new cranial nerve deficits, or bowel/bladder dysfunction should prompt urgent vascular imaging and possible neurosurgical consultation.

[1][12]

Was the onset of these symptoms acute or has this been a gradual progression? Also, is the patient on metformin, and has alcohol use been assessed? These details would significantly narrow the differential.

Degenerative Cervical Spondylosis.

The New England Journal of Medicine. 2020. Theodore N.Review

Clinical Reasoning: Reversible Gait Ataxia: From Wheelchair to Independent Mobility.

Neurology. 2017. Abkur TM, Bede P.Case

Clinical Reasoning: A 38-Year-Old Man With Involuntary Jerk-Like Movements and Ataxia.

Neurology. 2025. Gomez AC, Charra Castellani MB, Kurtz V, et al.RecentCase

Clinical Reasoning: A 47-Year-Old Man With Rapidly Progressive Ataxia and Vitiligo.

Neurology. 2020. Han F, Ren H, Tang M, Zhu Y, Guan H.Case

ACR Appropriateness Criteria® Dizziness and Ataxia: 2023 Update.

Journal of the American College of Radiology : JACR. 2024. Wang LL, Thompson TA, Shih RY, et al.Guideline

Neurological Disorders Caused by Novel Non-Coding Repeat Expansions: Clinical Features and Differential Diagnosis.

The Lancet. Neurology. 2024. Vegezzi E, Ishiura H, Bragg DC, et al.Review