The falling teacup: a curious stroke case

A 63-year-old man presented with sudden-onset right index finger weakness that made him drop his morning teacup. He could not fully extend, adduct, and abduct his finger ([Figure 1]). A brain magnetic resonance imaging revealed a minor acute ischemic lesion on the left precentral cortex, in the hand knob (HK) area ([Figure 2]), of undetermined etiology.

Figure 1Photograph of the involved hand, evidencing a tendency toward the flexion of the right index finger, since the patient could not fully extend, adduct, and abduct it.

Figure 2Brain magnetic resonance imaging (axial section) displaying an acute infarction (white arrow) in the hand knob territory, presenting as an inverted omega (dashed line).

HK infarctions are uncommon, often cardioembolic, and can present with different patterns of isolated hand weakness[1]. This case illustrates the rare involvement of a single finger following HK stroke and strengthens the existence of finger somatotopy in human motor cortex[1],[2]. This observation helps clarifying motor cortex anatomy and clinical correlations, further detailing the Penfield’s homunculus[3], its first proposed somatotopic organization.

Conflict of interest:

There is no conflict of interest to declare.

Authors’ contributions:

AR: approached the patient, conceptualized the work, wrote the original draft, and revised the final draft; TG: approached the patient and revised the final draft; CG: oversaw the work, approached the patient, and revised the final draft.

• References

• 1 Finkelsteyn AM, Saucedo MA, Miquelini LA, Chertcoff A, Bandeo L, Pacha S. et al. Ischemic stroke of the “hand knob area”: A case series and literature review. J Clin Neurosci 2019; Mar; 65: 100-105 https://doi.org/10.1016/j.jocn.2019.03.025
• 2 Beisteiner R, Windischberger C, Lanzenberger R, Edward V, Cunnington R, Erdler M. et al. Finger somatotopy in human motor cortex. Neuroimage 2001; Jun; 13(6) Pt 1 1016-1026 https://doi.org/10.1006/nimg.2000.0737
• 3 Penfield W, Rasmussen T. The cerebral cortex of man: a clinical study of localization of function. JAMA 1950; Dec; 144 (16) 1412-1412 https://doi.org/10.1001/jama.1950.02920160086033

Publikationsverlauf

Eingereicht: 22. April 2021

Angenommen: 24. Juli 2021

Artikel online veröffentlicht:
30. Januar 2023