A second group of PME diseases belonging to the class of cerebral storage diseases usually involves myoclonus, visual problems, dementia, and dystonia (sustained muscle contractions that cause twisting movements or abnormal postures). Another group of PME disorders in the class of system degenerations often is accompanied by action myoclonus, seizures, and problems with balance and walking. Many of these PME diseases begin in childhood or adolescence. Treatment is not normally successful for any extended period of time. Reticular reflex myoclonus is thought to be a type of generalized epilepsy that originates in the brainstem, the part of the brain that connects to the spinal cord and controls vital functions such as breathing and heartbeat. Myoclonic jerks usually affect the whole body, with muscles on both sides of the body affected simultaneously. In some people, myoclonic jerks occur in only a part of the body, such as the legs, with all the muscles in that part being involved in each jerk. Reticular reflex myoclonus can be triggered by either a voluntary movement or an external stimulus. Diaphragmatic flutter
A very rare form includes the diaphragmatic flutter, the Belly Dancers Syndrome,: 2  or Van Leeuwenhoeks disease. It was first described by Antonie van Leeuwenhoek in 1723, who had it. : 2  The condition characterizes spoken communication that sounds like a short-breathed hiccup. These muscle spasms can recur dozens of times per day.
The individual ulcers (aphthae) recur periodically and heal completely, although in the more severe forms, new ulcers may appear in other parts of the mouth before the old ones have finished healing. Aphthous stomatitis is one of the most common diseases of the oral mucosa, and is thought to affect about 20% of the general population to some degree. The symptoms range from a minor nuisance to being disabling in their impact on eating, swallowing, and talking, and the severe forms can cause people to lose weight. There is no cure for aphthous stomatitis, and therapies are aimed at alleviating the pain, reducing the inflammation and promoting healing of the ulcers, but there is little evidence of efficacy for any treatment that has been used. Angular stomatitis
Inflammation of the corners (angles) of the lips is termed angular stomatitis or angular cheilitis. In children a frequent cause is repeated lip-licking, and in adults it may be a sign of underlying iron deficiency anemia, or vitamin B deficiencies (e.g., B2-riboflavin, B9-folate, or B12-cobalamin, which in turn may be evidence of poor diets or malnutrition such as celiac disease). Also, angular cheilitis can be caused by a patients jaws at rest being overclosed due to edentulousness or tooth wear, causing the jaws to come to rest closer together than if the complete/unaffected dentition were present. This causes skin folds around the angle of the mouth which are kept moist by saliva, which in turn favours infection; mostly by Candida albicans or similar species.