April 09, 2022
The spontaneous quivering of the jaw can make daily activities difficult. But why is the chin quivering? Is there something more to worry about? With several possible diagnoses, it is important to figure out the type of condition and possible treatment options. Geniospasm is just one condition of many.
What is geniospasm?
Geniospasm was first described by Massaro in Italian literature in 1894 and has since been reported in fewer than 50 families worldwide. The rare genetic disorder is characterized by involuntary repetitive tremors of the chin and lower lip with no other evidence of a nervous system abnormality. Usually, the condition first appears in infancy and early childhood and then lessens with age. But some teens and adults have also presented signs of the condition. Synonyms used for this rare condition include trembling chin and hereditary chin tremor, but it must be differentiated from palatal tremor, facial myokymia, and essential tremor affecting facial muscles.
The pathophysiology of geniospasm is not fully understood. The syndrome is often characterized by episodic, high-frequency contraction of the mentalis muscle. Episodes of trembling can be brought on by stress, emotion, or occur spontaneously. Episodes may occur during sleep or waking hours and can last from a few seconds to a few hours. Symptoms can be mild or include more irksome and frequent chin movements with involuntary tongue biting and lacerations.
Is there an effective treatment for geniospasm?
Because the pathophysiology is poorly understood and limited data exists, guidance on prognosis and management strategies for geniospasm are difficult. Doctors tend to evaluate the patient’s symptoms, ask about family medical histories, ask about any medications, perform a physical examination, and do some tests to rule out other conditions. Some of these other tests might include a blood test and an MRI scan of the brain.
Geniospasm is often described as a benign condition and if the quivering is mild, treatment may not be needed. In some cases, the trembling will often dissipate without intervention. But if the tremors persist and impact the quality of life or the patient’s ability to perform daily tasks or if it becomes socially disabling, the doctor may recommend certain medications. Historically, several treatments have been used with various outcomes. More recently, patients who have undergone injections of botulinum toxin or clonazepam have experienced a complete resolution of symptoms with no adverse effects.