Myotonia congenita — a diagnosis that can be made regardless of the patient’s age

A 76-year-old female patient was admitted to the Department of Neurology at the Norbert Barlicki Memorial Teaching Hospital No. 1 in Lodz, Poland, on account of gait problems and muscle stiffness.The woman retired at the age of 55, previously she had worked as a florist.She described her physical activity during childhood and adulthood as average.After she retired, she started practicing Nordic walking.The women noticed first symptoms about 2-3 years prior to the admission.The patient had a history of type 2 diabetes, hyperlipidemia, partial thyroidectomy, left hip replacement and bilateral cataract surgery.Family history of genetic diseases was negative.Upon neurological examination, exaggerated muscle tone in lower limbs was observed.Percussion revealed myotonia in the flexor hallucis brevis muscle and delayed grip release of toes in both lower extremities.Initially, no such symptoms were present in the upper limbs; however, they appeared within several months of follow-up.Upon examination no abnormalities were found in cranial nerve function.No pyramidal, cerebellar or extrapyramidal signs were present.Magnetic resonance imaging of the brain and the spinal cord performed before admission to the hospital showed no significant changes.During hospitalization, serum and cerebrospinal fluid parameters were examined.Number of