Benign Paroxysmal Torticollis Of Infancy
A rare, transient paroxysmal dystonia characterized by onset of recurrent episodes of torticollic posturing of the head between infancy and early-childhood.
Epidemiology
To date, more than 150 cases have been described in the literature; however, the disease is likely under reported. The condition appears to be slightly more frequent in females.
Clinical description
Onset typically occurring between 2 and 8 months of age but may occur anywhere between birth and early childhood with episodes occurring between every few weeks and every few months. The duration of the torticollis varies between patients, but usually lasts from a few hours to a few days (although persistence for over one week has been reported). The torticollic episodes (in particular those of shorter duration) may by associated with other symptoms including vomiting, pallor, sweating, apathy or irritability, an unsteady gait, an upwardly-diverted gaze, abnormal truncal posture (tortipelvis) and contraction of the posterior neck muscles (retrocollis). The frequency and duration of the torticollic episodes decreases with age and episodes usually stop completely by 5 years of age.
Etiology
There is some clinical and genetic evidence pointing to benign paroxysmal torticollis as one of the infantile migraine precursors. In some cases disease-causing mutations have been identified in the CACNA1A (19p13.13). In one case, a mutation in PRRT2 (16p11.2) has been identified. Both CACNA1A and PRRT2 have been linked to other diseases such as familial hemiplegic migraine.
Diagnostic methods
Diagnostic criteria include i) recurrent attacks in infants and small children ii) head tilt to either side that remits spontaneously after minutes to days iii) one of the following symptoms: pallor, irritability, malaise, vomiting and ataxia which may coexist during attacks iv) normal neurological examination between attacks v) not attributed to another disorder. As the disorder is benign and transient, extensive investigations should be avoided, although some diagnostic tests (brain ultrasound, computerized tomography, magnetic resonance imaging, studies of toxics or drugs and otorhinolaryngological examination), all giving normal results, may be required mainly in the first episode to exclude other causes of torticollis.
Differential diagnosis
The differential diagnosis (mainly in the first episode) should include intoxication, undesirable secondary effects of drugs, craniocervical junction abnormalities such as atlanto-axial instability, Arnold-Chiari malformation, epilepsy, vertigo, Sandifer's syndrome and posterior fossa tumors in cases with associated symptoms.
Genetic counseling
The disorder usually occurs sporadically; however, a few families with autosomal dominant inheritance have been reported.
Management and treatment
As the disease is self-limiting and resolves spontaneously by mid-childhood, no treatment is usually required. There is no approved medication for this disease.
Prognosis
Prognosis is excellent.