Letters to the Editor 833

1 Kennedy WR, Alter M, Sung JH. Progressive seemed in the first days to originate exter- The inhibition was revealed in our studies proximal spinal and bulbar muscular atro- phy of late onset: a sex-linked recessive trait. nally and was heard bilaterally. The melody during a period of voluntary contraction by J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.56.7.833 on 1 July 1993. Downloaded from Neurology 1968;18:671-80. she heard was extremely loud, leading her stimulating the at a strength 2 Harding AE, Thomas PK, Baraister M, to ask surrounding people to turn off the lower than that required to produce excita- Bradbury PG, Morgan-Hughes JA, radio, which she believed to be the source tion under the same conditions. A recent Ponsford JR. X-linked recessive bulbospinal neuronopathy: a report of ten cases. J Neurol of the tune. The music began suddenly, was study has reported that the discharge of Neurosurg Psychiatty 1982;45: 1012-19. slow, clear and reminiscent of popular motor neurons in the first dorsal interosseus 3 Mukai E, Mitsuma T, Takahashi A, Sobue I. songs that she had heard in her youth, but muscle of the hand of a patient with multi- Endocrinological study of hypogonadism and feminization in patients with bulbar were still unknown to her. She was able to ple sclerosis could be suppressed by tran- spinal muscular atrophy. Clin Neurol sing this melody. Shortly after the onset of scranial magnetic stimulation of the motor (Tokyo) 1984;24:925-9. this phenomenon, she gained full insight cortex, but this was not observed in normal 4 Sobue G, Hashizume Y, Mukai E, Hirayama into the problem and realised that this subjects.4 In our previous studies'-3 we aver- M, Mitsuma T, Takahashi A. X-linked recessive bulbospinal neuronopathy, a incessant tune originated in her own mind. aged the rectified surface electromyogram clinico-pathological study. Brain 1989;112: The volume was variable and sometimes the (EMG) to reveal inhibition of voluntary 209-32. melody was enjoyable; the volume was contraction in a number of different arm 5 Mukai E. Clinical course and prognosis of bulbo-spinal muscular atrophy. Neurol mostly high, especially during the night, dis- and hand muscles. We have now re-investi- Therapeut (Tokyo) 1991;8:519-22. turbing her sleep, and severely interefering gated one of our subjects to examine the 6 LaSpada AR, Wilson EM, Lubehn DB, with her daily activities. Amitriptyline par- effect of transcranial magnetic stimulation Harding AE, Fischbeck KH. Androgen tially helped her sleep. The intensity of the on the probability of discharge of single receptor gene mutations in X-linked spinal and bulbar muscular atrophy. Nature music diminished during the following motor units in the first dorsal interosseus 1991;352:77-9. weeks, but the same melody persisted. muscle. We can confirm that transcranial 7 Murray V. Improved double-stranded DNA Musical hallucinations after are magnetic stimulation at a strength which sequencing using the linear polymerase three cases, all with causes a reduction in surface EMG, chain reaction. Nucleic Acids Res 1989;17: reported rarely. Only gross 8889. right hemispheric pathology, were quoted in and is sub-threshold for excitation, does 8 Doyu M, Sobue G, Mukai E, et al. Severity of a recent review.' Our patient illustrates the lower the probability of discharge of indi- X-linked recessive bulbospinal neuronopa- fact that dominant hemispheric stroke can vidual motor units in normal humans. thy correlates with size of the tandem CAG repeat in androgen receptor gene. Ann also result in musical hallucinations. The subject was a right handed male (age Neurol 1992;32:707-10. As with several other reported cases, 49 years) with no history of neurological ill- 9 Doyu M, Sobue G, Mukai E, Takahashi A, including that of Paquier et al, our patient ness. Local ethical approval for the study Mitsuma T. DNA diagnosis of X-linked had for was obtained and the subject gave his recessive bulbospinal muscular atrophy by suffered from loss many androgen receptor gene mutations. Clin years. Berrios in a review, pointed out that informed consent to the procedures. Two Neurol (Tokyo) 1992;32:336-9. musical hallucinations are far more com- forms of electromyographic recordings were 10 Fu Y-H, Kuhl DPA, Pizzuti A, et al. Variation mon in elderly, hearing impaired, female made from the first dorsal interosseus mus- of the CGG repeat at the fragile X site results in genetic instability; resolution of patients.' It is possible that musical hal- cle of the right (dominant) hand. To record the Sherman paradox. Cell 1991;67: lucinations represent a "deafferentation" gross EMG, surface electrodes were placed 1047-58. phenomenon, reminiscent of visual halluci- over the belly of the muscle and at an indif- 11 Harley HG, Rundle SA, Reardon W, et al. nations in the blind, thalamic pains or ferent point over the proximal interpha- Unstable DNA sequence in myotonic dys- trophy. Lancet 1992;339:1125-8. phantom limb. It appears that both central langeal joint of the first digit. A concentric 12 Forest MG, Lecoq A, David M, Pugeat M. and end organ pathology contribute to the needle electrode was inserted percuta- Effects of human chorionic gonadotropin, appearance of musical hallucinations.2 The neously into the first dorsal interosseus androgens, adenocorticotropin hormone dexamethasone and hyperprolactinemia on prolonged lack of normal input to cortical muscle to record the discharges of single plasma sex steroid-binding protein. Ann N areas involved in hearing, due to peripheral motor unit. The subject was required to YAcad Sci 1988;538:214-34. disease, might cause a specific vulnerability make a weak voluntary contraction of the which results in the generation of this muscle. Auditory feedback of the signal was abnormal sensation following a central provided to enable the subject to recruit insult. Appropriately, Wengel et al entitled and maintain the discharges of a motor unit their manuscript "musical hallucinations, that could be reliably identified and selected the sounds of silence?",3 as they occur when for peri-stimulus time histogram analysis. the mind is chronically deprived from music Transcranial magnetic stimulation was MATTERS and sound. delivered from a Novametrix 200 stimulator http://jnnp.bmj.com/ RIVKA INZELBERG using a 9 cm round coil centered over the SIMONA VISHNIEVSKAYA ARISING AMOS D KORCZYN vertex. The initial direction of current flow Department ofNeurology, in the coil was anticlockwise and adequate Tel-Aviv Sourasky Medical Center, stimuli preferentially excited muscles on the Tel-Aviv, Israel right side. Transient musical hallucinosis 1 Berrios GE. Musical hallucinations. Br J The threshold transcranial magnetic Psychiatry 1990;156:188-194. stimulation required to produce an initial sur- Paquier et al reported a patient who, follow- 2 Hammeke TA, McQuillen MP, Cohen BA. excitatory response, gauged from the on September 27, 2021 by guest. Protected copyright. Musical hallucinations associated with face EMG recording, was 40% of maximum ing subarachnoid haemorrhage, developed acquired deafness. J Neurol Neurosurg musical hallucinosis. Based on a literature Psychiany 1983;46:570-2. output. The response had a latency of 23 review, they suggested that musical halluci- 3 Wengel SP, Burke WJ, Holemon D. Musical ms and was followed 5-8 ms later by a nosis, formed auditory perceptions that hallucinations-The sounds of silence? JAm period of suppressed EMG lasting 30 ms Soc occur in the absence of external acoustic Geriatr 1989;37:163-166. and culminating in a late period of stimulus while the patient is aware of their increased EMG activity. Part A of the figure non-real nature, may result from lesions of shows the average of the full-wave rectified either side of the brain, and not necessarily surface EMG response to 50 magnetic stim- from the non dominant hemisphere, as pre- Inhibition of motor unit discharge in uli at 37% of output. At this strength of viously proposed.' A patient recently seen humans evoked by transcranial stimu- stimulation no initial excitation occurs but by us reinforces the authors' conclusion. lation suppression of EMG is evident with a A 75 year old right handed woman had latency of 29 ms and duration 26 ms. The been suffering from severe due Transcranial magnetic stimulation of the peri-stimulus time histogram in part B of to streptomycin use for about 30 years. Her motor cortex can elicit contraction of con- the figure is constructed from the discharges past history revealed non insulin dependent tralateral muscles but, until recently, there of a single motor unit (average frequency diabetes mellitus, ischaemic heart disease, had been no reports that transcranial mag- 9 1 impulses/s) during 100 magnetic stimuli peripheral vascular disease and paroxymal netic stimulation could suppress muscle also at 37% of maximal output. A profound atrial fibrillation. In September 1992, she contraction. We have shown' that inhibition depression of firing occurs also lasting suddenly developed right hemiparesis and of voluntary contraction can be elicited by 26 ms and with a latency of 29 ms. Within dysphasia which recovered within a few transcranial magnetic stimulation and have the period of suppressed firing the unit dis- weeks. Her CT scan revealed a left thalamic presented evidence2 3that the mechanism is charges on only 8 occasions during the 100 infarction, mild cortical atrophy and ven- likely to be supraspinal, presumably involv- trials. The number of counts expected for tricular enlargement. A few days after the ing inhibition of corticospinal neurons with that period of the peri-stimulus time his- event, she started hearing a melody, which consequent disfacilitation of motor neurons. togram in the absence of stimulation was