Holmes tremor following midbrain hemorrhage - An illustrative case.

Background: Holmes tremor (HT) is a rare, low-frequency tremor that presents at rest, during posture maintenance, and with intentional movement - associated with structural damage to the midbrain, thalamus, or cerebellothalamic pathways. Although vascular causes are well established, HT resulting from mesencephalic hemorrhage complicated by obstructive hydrocephalus has not been previously reported in the literature. Case Description: A 71-year-old male developed acute left hemiparesis and dysarthria following traumatic brain injury. Neuroimaging revealed right ponto-mesencephalic hemorrhage extending into the superior cerebellar peduncle, with infarction near the right tentorial edge and compression of the fourth ventricle, leading to supratentorial hydrocephalus. One-week post-trauma, the patient exhibited a right-sided tremor with resting, postural, and kinetic components, consistent with HT. Pharmacologic treatments, including antiepileptics, failed to produce clinical improvement. Serial imaging ruled out vascular malformations. Given patient's progressive neurological recovery, a non-surgical, conservative management strategy was adopted. Conclusion: This case highlights a rare manifestation of HT secondary to mesencephalic hemorrhage complicated by obstructive hydrocephalus. The delayed onset and resistance to pharmacologic therapy emphasize the diagnostic and therapeutic complexity of HT. Clinicians should be vigilant in recognizing this condition in similar clinical scenarios and consider a tailored strategy, including delayed consideration of functional neurosurgery once hydrocephalus has stabilized.