Gamstorp episodic adynamy is the name taken by Hyperkalemic periodic paralysis (HYPP) when it occurs in humans. Usually, HYPP (known as Impressive Syndrome as well), is a disorder that affects the channels for sodium in the muscle cells, and incapacitates regulation of potassium in the blood. This disorder, with autosomal dominant inheritance, is also a disease that affects horses.

While rare, the HYPP has also been observed in humans. It manifests as episodes characterized by extreme muscle weakness. The onset of these symptoms usually begin around the age of 20 years old, and, depending on the severity of the disease, may increase or may stabilize until the person suffering from Gamstorp episodic adynamy is well within his or her 40's or 50's. Some known triggers of Gamstorp episodic adynamy are resting after exercise, consumption of food rich in potassium, stress and fatigue, cigarette smoke, and fasting. While muscle strength can recover in between Gamstorp episodic adynamy attacks, many people suffering from this disease may experience the said muscle weakness increasingly over time. Stiffness and spasms in the muscles may also happen. Another symptom is the increased levels of potassium in the blood, particularly during muscle weakness attacks. The consumption of potassium by individuals suffering from the disease may trigger attacks of muscle weakness regardless of increased potassium levels in the blood.

gamstorpepisodicadynamy