The missed missing hole.
At times in clinical neurology, the identification of a subtle clinical or radiological sign can lead to prompt diagnosis of a very rare or difficult case. We report on a patient who presented with untreatable headache and unilateral ptosis. Computed tomography (CT) scan of the head did not reveal any structural cause. Magnetic resonance angiogram showed absence of left internal carotid artery, which was eventually confirmed by a catheter angiography. Reviewing the case, it emerged that a feature on the initial CT scan "bone window" would have confirmed the diagnosis, had it been searched for: the underdeveloped carotid canal, which is a consequence and a marker of internal carotid artery agenesis.
Behavorial and Cognitive Neurology Unit, Department of Neurology, Cognitive Disorders Reference Center, Hospital das Clínicas, University of São Paulo, São Paulo, SP, Brazil.
Fábio Henrique de Gobbi
FH
Porto
Mari-Nilva Maia da
MN
Silva
João Roberto Sala
JR
Domingues
Gislaine Cristina Lopes Machado
GC
Porto
Indran
I
Davagnaman
Ricardo
R
Nitrini
D000328:Adult; D002343:Carotid Artery, Internal / Q000002:abnormalities*; D002533:Cerebral Angiography; D003937:Diagnosis, Differential; D005260:Female; D006732:Horner Syndrome / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging; D014057:Tomography, X-Ray Computed