A new mutation (Thr106Ile) of the GTP cyclohydrolase 1 gene associated with DYT5 dystonia (Segawa disease)
✍ Scribed by Etsuro Ohta; Itaru Toyoshima; Manabu Funayama; Hiroshi Ichinose; Kazuko Hasegawa; Fumiya Obata
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 94 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0885-3185
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✦ Synopsis
and based on circumstantial evidence. The exact diagnosis was not appreciated by the treating physicians during the acute phase and hence no therapeutic benefit that could have been obtainable with intravenous anticholinergics was tested. However, the onset of the laryngospasm soon after receiving parenteral haloperidol and its spontaneous resolution and no recurrence after drug discontinuation surely point to a causal relationship. No other cause of laryngospasm could be established, no benefit was obtained by treatment for possible anaphylaxis, and no edema glottis was detected on laryngoscopy.
The fact that laryngeal muscles may be affected in patients with tardive dyskinesia is not often appreciated. 1,2 Acute laryngel dystonia following exposure to neuroleptics is indeed rare but probably is also underreported. Flaherty and Lahmeyer 3 were the first to suggest that sudden death following phenothiazine exposure might be due to acute laryngeal dystonia. Kock and Pi 4 reviewed nine cases of neuroleptic-induced acute laryngel dystonia. Six patients were young men and all episodes of laryngospasm occurred within 8 days of initiating treatment. Most patients received only a modest dose of neuroleptics, implying that there may be individuals with heightened susceptibility for acute dystonia. Apart from haloperidol, isolated reports of such laryngeal dystonia causing stridor have been made, associated with the use of other neuroleptics and antiemetics. [5][6][7] If detected early, the condition may be treated with botulinum toxin or intravenous anticholinergics, but severe cases may need tracheostomy as a lifesaving measure.
The present case almost certainly had laryngeal dystonia with stridor induced by haloperidol. It is to be noted, of course, that he also received 4 mg of risperidone. Extrapyramidal side effects of risperidone are much less common than with haloperidol. Also, these have been reported with chronic treatment with high-dose risperidone specially in schizophrenic patients but include a single report of spasmodic dysphonia. 8 Acute dystonic reaction related to short course of risperidone therapy must be very rare. 9 In the present case, there had been some delay in recognition. First, the stridor was initially thought to be due to an anaphylactic drug reaction and this indeed had been mentioned in the literature. 10 Second, there had been delay in finding the offending agent (haloperidol seemed more likely than risperidone). A high index of suspicion is the key to early recognition and institution of appropriate therapy. The present case, of course, recovered spontaneously before the real diagnosis was made.