Specificity of "peering at the tip of the nose" for a diagnosis of thalamic hemorrhage.
BACKGROUND
Tonic inward and downward deviation of the eyes ("peering at the tip of the nose") is regarded as a unique feature of thalamic hemorrhage, but the mechanisms of this ocular finding remain obscure.


OBJECTIVE
To describe 4 patients who showed tonic inward and downward deviation of the eyes from brainstem or thalamic lesions and to discuss the possible mechanisms involved.


METHODS
Case report.


METHODS
Secondary and tertiary referral hospitals.


RESULTS
One patient developed alternating esotropia with downward ocular deviation from thalamic hemorrhage compressing the midbrain. Two patients showed multiple infarctions in the territory of the posterior circulation with or without the involvement of the thalamus. Another patient had lateral pontine hemorrhage extending up to the midbrain tegmentum. Ocular bobbing preceded or accompanied tonic ocular deviation in 3 patients.


CONCLUSIONS
Tonic inward and downward deviation of the eyes may develop in thalamic or brainstem lesions. Irritation or destruction of the neural structures involved in the vergence and vertical gaze may cause this ocular sign in mesodiencephalic lesions. Skew deviation and esotropia from abduction deficit may be involved in some patients. Ocular bobbing and tonic downward deviation may share a common pathogenesis.
Choi
Kwang-Dong
KD
Department of Neurology, Pusan National University School of Medicine, Pusan, Korea.
Jung
Dae Soo
DS
Kim
Ji Soo
JS
D000368:Aged; D002543:Cerebral Hemorrhage / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000209:etiology*; D012680:Sensitivity and Specificity; D013788:Thalamus / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods