A case report: Numb Chin Syndrome due to thalamic infarction: a rare case

Abstract

BackgroundNumb Chin Syndrome (NCS), which is also characterized as sensory neuropathy of the mental nerve, describes a mostly unilateral numbness of the chin and lower lip. Benign and malignant diseases are known to cause this circumscribed symptom, which can easily be overlooked or misdiagnosed. In this article we present the very rare case of a clinical NCS caused by thalamic lacunar infarction. As a pure sensory stroke it is a rare variant of the Cheiro-Oral Syndrome (COS).Case presentationA 63-year-old male patient received an emergency referral to our department after the patient had noticed a feeling of numbness of the left lower lip and chin on the previous day. The neurological examination revealed an approximately 2 × 3 cm area of hypoesthesia in the area of the chin and left lower lip and the cranial MRI an acute ischemia in the right thalamus.ConclusionsIn this case report we introduce a patient who clinically shows an NCS. Various diseases may be responsible for NCS, including malignancies or even central neurological disorders such as multiple sclerosis. A lacunar thalamic ischemia as a cause of NCS is very rare and to our knowledge described in the literature only in the contex of a COS in three cases. We wish to remind the reader, through this case, of the purely descriptive and syndromal character of the NCS and the importance for detecting underlying diseases. Furthermore we give a brief overview of the NCS and causative disorders.

Numb Chin Syndrome in Sickle Cell Disease: A Systematic Review and Recommendations for Investigation and Management

“…Importantly, the mandibular region must be included in the scanned region, which is not always the case with a standard brain MRI; otherwise, important anatomical findings may be missed [ 43 ]. Although central neurological causes of the numb chin are probably extremely rare, a thalamic lacunar infarct can present such circumscribed symptoms [ 44 ]. Since patients with sickle cell disease have a heightened risk of stroke, this possibility should be considered.…”

Numb Chin Syndrome Associated with Residual Ridge Resorption in Edentulous Mandible: Report of a Case

“…The positioning of the mental foramen nearby the residual ridge crest has frequently been accompanied by the subjective pain and paresthesia felt under mandibular dentures due to pressure on the superficially located mental nerve (Murray, 1994;Närhi et al, 1997). This sensory neuropathy of the mental nerve, which is typically characterized by unilateral numbness in the chin and lower lip, is called "numb chin syndrome" (Rimmele et al, 2019).…”