Clinical features, etiology, and prognosis of hand knob stroke: a case series

Abstract

Background Hand knob stroke is a rare clinical disorder frequently misdiagnosed as peripheral neuropathy. The purpose of this study is to recognize this particular type of stroke by analyzing clinical features, etiology, and prognosis. Methods We enrolled 19 patients with acute hand knob stroke in the Department of Neurology of the Beijing Geriatric Hospital from January 2018 to January 2022, and the clinical and imaging data of the patients during hospitalization and follow-up were collected and summarized. Results Acute hand knob stroke accounted for 0.9% of all acute stroke, and ischemic stroke (17 cases, 89.5%) was more than hemorrhagic stroke (2 cases, 10.5%). All patients presented sudden contralateral hand paresis, 12 (63.2%) of them had only isolated hand paralysis, and the location of the lesion corresponded to different finger weakness. The cause of hand knob hemorrhage was hypertension, while the causes of hand knob infarction were mainly small-vessel occlusion (SVO) (35.3%) and large-artery atherosclerosis (LAA) (35.3%), and the rare causes include carotid artery dissection and carotid body tumor. After a median follow-up 13.5 months, the prognosis of 94.7% patients was good, and one patient (5.3%) had recurrent stroke. Conclusions Hand knob stroke is a rare stroke with a good prognosis and a low stroke recurrence rate. Ischemic stroke is the predominant type and the main clinical manifestation is hand paresis. The cause of hand knob hemorrhage is hypertensive, while SVO and LAA are the main causes of hand knob infarction, but there are some rare etiologies.

A Narrative Review of Stroke of Cortical Hand Knob Area

“…Wang et al reported that hyperhomocysteinemia was the most common risk factor for hand knob infarction [16], while Orosz et al considered that hypertension was the most common [15]. This last finding was also found by Zhang et al, who observed that hypertension was the most frequent risk factor in patients with hand knob stroke, followed by hyperlipidemia and hyperhomocysteinemia [23]. The table describes the incidence of hand knob stroke in different epidemiological studies (Table 2).…”

“…Imaging findings might not be read accurately as the area of the stroke is small, and the pretest probability of stroke would be low. These factors contribute to the low prevalence of reported hand knob strokes, although the actual number of cases may be higher [23]. Additionally, lack of cortical, pyramidal, and cerebellar symptoms results in evaluating physicians favoring a peripheral source.…”

Pseudoulnar palsy with concurrent wrist drop: case report

“…A subsequent case series evaluated the imaging findings of hand knob stroke patients and found that in the majority of ischaemic stroke events, there was variation in the brain lesions, with lesions being present either in the territory of the hand knob or distributed along the path of the MCA. Thirty-one percent of these cases involved medial lesions that resulted in ulnar finger weakness 10 .…”

Pure Motor Isolated Finger Palsy by Cerebral Infarction: Tips for Diagnosis by Neurological Examination

“…Some cases are accompanied by sensory disturbance or cortical symptoms among their previous reports, whereas reports of pure motor isolated finger palsy (PMIFP) caused by localized lesions in the cerebrum without other neurological symptoms except finger palsy are rare [1]. In cases of finger palsy, including PMIFP, PMM, IHP, and IFP, the cerebral localization is typically an infarct in the precentral knob (PK) region characterized by an inverted omega shape on brain images, including computed tomography (CT) or magnetic resonance imaging (MRI) [1,[3][4][5][6]. While the above differential diagnosis is listed for unilateral finger palsy, there is no literature reporting detailed differential points in clinical findings, including neurological findings, because of limited reports of PMIFP by cerebral infarction.…”