Percheron Artery-Plus Syndrome: A Syndrome Beyond Stroke Chameleon

The artery of Percheron (AOP) is an anatomical variant of the thalamoperforating arteries. AOP occlusion can cause bilateral paramedian thalamic infarctions and is referred to as a "stroke chameleon" because it lacks the classic signs of stroke. Coexistence of AOP occlusion and other neurologic disease is rare and can cause disturbance of consciousness. A 78-year-old woman had acute onset of left limb weakness and drowsy consciousness. Brain magnetic resonance angiography (MRA) revealed acute bilateral paramedian thalamic infarctions. However, serum and cerebrospinal fluid (CSF) cryptococcal antigen titers were 1:16 and 1:128, respectively. The CSF culture grew Cryptococcus neoformans. Although consciousness and muscle power improved after treatment, the patient later died of pneumonia. A 68-year-old woman developed acute disturbance of consciousness followed by delirium. Brain MRA revealed acute bilateral paramedian thalamic infarctions. Elevated free thyroxine, anti-thyroperoxidase, and anti-thyroglobulin antibodies were detected. She received 3 days of steroid pulse therapy followed by oral prednisolone. Her consciousness gradually improved after Hashimoto encephalopathy and stroke were controlled. AOP occlusion was diagnosed early in these two patients. However, other concomitant life-threatening diseases could have been overlooked because of the complicated diagnostic determination. Further serum cryptococcal antigen, anti-TPO Ab, and anti-TG Ab surveys might help to exclude cryptococcal meningitis and Hashimoto encephalopathy. CSF study is warranted when central nervous system infection is strongly suspected. This "Percheron artery-plus syndrome" comprises multifaceted disorders beyond the stroke chameleon and requires attention.

Selective Hand Motor Cortex Lesions Masquerading as "Pseudoperipheral Nerve Palsy"

Strategic cortical lesions involving the hand motor cortex (HMC) presenting acutely as distal upper limb pure motor weakness certainly do need to be differentiated on clinical grounds from “pseudoperipheral palsy.” This rare phenotype can imitate peripheral motor nerve deficits and should not be easily overlooked. The isolated “central hand and finger weakness” presenting as an acute onset of varying combinations such as pseudomedian, pseudoradial, and/or pseudoulnar nerve palsy is intriguing to the novice. In literature, this phenotype has been reported solely to result from cortical cerebral infarction and documented to occur in <1% of all ischemic strokes. The apropos of six “unforgettable patients” here highlights the heterogeneous pathophysiologic etiologies and mechanisms that included not only the conventional stroke risk factors but also hyperhomocysteinemia, common carotid artery thrombosis due to hyperhomocysteinemia and severe iron-deficiency anemia, biopsy-proven giant cell arteritis (GCA), cerebral metastasis, and dilated cardiomyopathy-related left ventricular thrombosis. Physicians and neurologists alike, as clinicians, need to be familiar with the peculiarities and clinical presentations of central hand control network cortical lesions.