[Claude syndrome caused by mesencephalic infarction: 2 cases]

Area of Science:

• Neuroscience
• Neurology
• Neuroanatomy

Background:

• Paramedian midbrain infarcts involving oculomotor nerve fibers are uncommon.
• Claude's syndrome is characterized by a combination of third cranial nerve palsy and contralateral cerebellar ataxia.

Observation:

• Two cases presented with third cranial nerve palsy and contralateral cerebellar ataxia.
• CT scans revealed paramedian midbrain tegmental infarcts in both cases.
• Oculomotor nerve fascicular palsies varied in severity, from complete to selective extraocular muscle involvement.

Findings:

• The observed clinical presentation and imaging findings are consistent with Claude's syndrome.
• Selective involvement of oculomotor functions suggests a specific intraaxial fascicular organization of the third cranial nerve within the brainstem.

Implications:

• Understanding the precise fascicular organization of the third cranial nerve is crucial for diagnosing and localizing midbrain lesions.
• These findings contribute to the neuroanatomical understanding of brainstem pathways and their clinical manifestations.
• Further research into the detailed neuroanatomy of cranial nerves in the midbrain can improve clinical diagnosis of specific stroke syndromes.