Bobble-head doll syndrome

Bobble-head doll syndrome is a rare neurological movement disorder in which patients, usually children around age 3, begin to bob their head and shoulders forward and back, or sometimes side-to-side, involuntarily, in a manner reminiscent of a bobblehead doll. The syndrome is related to cystic lesions and swelling of the third ventricle in the brain. Symptoms of bobble-head doll syndrome are diverse but can be grouped into two categories: physical and neurological. The most common form of treatment is surgical implanting of a shunt to relieve the swelling of the brain. Bobble-head doll syndrome is a rare neurological movement disorder in which patients, usually children around age 3, begin to bob their head and shoulders forward and back, or sometimes side-to-side, involuntarily, in a manner reminiscent of a bobblehead doll. The syndrome is related to cystic lesions and swelling of the third ventricle in the brain. Symptoms of bobble-head doll syndrome are diverse but can be grouped into two categories: physical and neurological. The most common form of treatment is surgical implanting of a shunt to relieve the swelling of the brain. Bobble-head doll syndrome is first reported as a movement disorder in patients. However, after performing several tests and scans of the brain, the characteristic movement is found to be neurological in origin. The main physical symptom of bobble-head doll syndrome is the most obvious to diagnose and involves two to three bobs per second of the head, which can sometimes also include the shoulders and upper torso. The patient is unaware of the movements and unable to control them unless directed to stop or given simple mental tasks such as basic arithmetic or spelling words. However, once the task is completed by the patient, the bobbing tends to resume after about a minute. Thus, the bobbing is described by doctors as volitional, or able to be stopped by making a conscious decision. The bobbing also disappears while the patient is asleep, a common feature of most movement disorders. A supplemental symptom of the head bobbing is a presence of ataxia. Several patients were reported as having difficulty walking, running, and climbing steps because of the bobbing. It is likely that the constant bobbing has interrupted the patient’s ability to balance which requires input from several sources including the vestibular, ocular, somatosensory, and motor systems. Although the nature of these movements is physical, their source is neurological, generally stemming from a dysfunction of parts of the nervous system which control motor function. A typical symptom in patients diagnosed with bobble-head doll syndrome is an enlargement of the head due to accumulation of cerebrospinal fluid in the third ventricle. This dilatation impairs communication between ventricles as well as the function of other surrounding structures. Quite often, the swelling is present along with cystic lesions in the third ventricle or surrounding periventricular structures. In reference to bobble-head doll syndrome, a third ventricular cystic lesion causes an obstruction in the foramina of Monro, which communicates with the lateral ventricles, and the proximal, cerebral aqueduct of Sylvius, which communicates with the fourth ventricle. It has also been reported to be caused by a cystic choroid plexus papilloma of the third ventricle and obstructive hydrocephalus. It is this blockage that is thought to produce the characteristic bobble-head movements. Other patients have seen the onset of bobble-head doll syndrome from the presence of a suprasellar cyst in the arachnoid mater of the meninges. It, too, obstructs the foramen of Monro. Those susceptible to acquiring bobble-head doll syndrome range from newborns to adults—with the oldest reported patient being 26 years old. However, the majority of cases involve children who have yet to reach puberty. Although the exact pathogenesis of bobble-head doll syndrome is still unknown, there are many theories as to how and why it does what it does. Most of these theories acknowledge the striking similarity of symptoms between bobble-head doll syndrome and other movement disorders. The presence of cystic lesions, causing swelling in the third ventricle, is a common feature in all patients. It is this dilatation that causes pressure to be applied to the surrounding structures of the third ventricle, such as the diencephalon. It is possible that the back and forth movement of fluid within the cyst causes rhythmic pressure on the diencephalic motor pathways. One of the key periventricular structures in that pathway is the thalamus which is responsible for relaying motor signals to the cerebral cortex as well as regulating consciousness, sleep, and alertness. The disappearance of the head movements while asleep implies that their origin may lie within the extrapyramidal system which is a part of the motor system that controls coordination of movement. The tracts associated with the extrapyramidal system are controlled by various structures of the central nervous system, such as the cerebellum and basal ganglia. The basal ganglia plays a large part in controlling motor function and thus, abnormalities to this system can result in movement disorders such as Parkinson’s Disease and dyskinesia, both of which share commonalities with bobble-head doll syndrome.