307 U 0 1U 13 LU 3 Figure: EMG activity and sound from hamstrings in standing patient with primary orthostatic tremor A=raw records of surface EMG and sound from hamstnngs. B=power spectrum of muscle sound from 0-25 Hz (and 0-300 Hz in inset). C=power spectrum of EMG. There is a clear peak at 15 Hz in spectra of sound and EMG. D=coherence between muscle sound and EMG. Horizontal line is level of 5% significance. There is striking coherence at around 15 Hz. is only present on standing. It is not heard when healthy subjects stand, and is due to the vibration set up by the rhythmic and synchronous contraction of muscle motor units in primary orthostatic tremor. The upper and lower traces in figure A show EMG activity and sound picked up by surface electrodes and microphone over hamstrings in a patient with this condition. The rhythmic grouped discharge of motor units occurs at about 15 Hz, with muscle sound paralleling this. The latter is confirmed in power spectra of the signals in B and C. Figure D shows that the microphone provides an exceptionally close translation of the muscle events, with coherence between EMG and muscle sound approaching unity in the frequency band of interest. It is this 15 Hz oscillation that is heard with the stethoscope, either at this fundamental frequency or at harmonics thereof. Thus simple auscultation may identify the abnormal muscle activity in orthostatic tremor without recourse to EMG recordings. P Brown National Hospital for Neurology and Neurosurgery and MRC Human Movement and Balance Unit, Institute of Neurology, London WC1N 3BG, UK 1 Heilman KH. Orthostatic tremor. Arch Neurol 1984; 41: 880-81. 2 Britton TC, Thompson PD, van der Kamp W, et al. Primary orthostatic tremor: further observations in six cases. J Neurol 1992; 239: 109-17. Ciprofloxacin for multiresistant enteric fever in pregnancy SiR-Multiresistant Salmonella typhi has caused several epidemics of typhoid fever in the Indian subcontinent in recent years,’ 1 and the fluoroquinolone antibiotic ciprofloxacin has become the main drug for management of the disease. Although the drug is not advised for patients younger than 18 years, it has also been used in children with enteric fever with reasonable safety; Karande and Kshirsagar2 argued that its adverse effects profile is similar in adult and paediatric populations. Ciprofloxacin did not affect the physiological development of the fetus in cynomolgus monkeys when fed in doses up to 200 mg/kg and there was no increase in spontaneous abortions.3 Since the drug can cause arthropathy in juvenile animals, its use in pregnancy is recommended only if the potential benefits outweigh possible risks to the mother and the fetus. In the northern Indian state of Jammu and Kashmir, we have used ciprofloxacin in many patients with good safety and efficacy. During our 6 years of experience with the drug we had to use it for seven pregnant patients with multi-drug- resistant enteric fever (MDREF). The patients (table) were admitted with pyrexia of varying duration that had not responded to antibiotics safe for use in pregnancy. Three women had anicteric hepatitis, one cholecystitis, and one pericardial effusion complicating the MDREF. In-vitro sensitivity patterns of the S typhi grown on blood culture showed resistance to ampicillin, co-trimoxazole, chloramphenicol, and tetracycline with variable sensitivity to cefotaxime (three), cefazolin (two), gentamicin (three), amikacin (six), and kanamycin (four). All the strains were sensitive to ciprofloxacin. Each patient received 5-7 days’ cefotaxime, to which there was no response. After we had explained the possible risks to the fetus and obtained consent, the patients started on ciprofloxacin 200 mg twice daily intravenously then switched to 500 mg twice daily by mouth on the 4th or 5th day. In all seven patients the fever resolved in 4-7 days (median 5). The drug was continued for 2 weeks in each case, with the dose halved after 8 days. The patients were followed up with weekly obstetric visits and regular ultrasonographic assessment. All the pregnancies carried to term and healthy babies were born spontaneously with vertex presentation. Apgar scores were all 8 or higher, and no congenital abnormalities were noted. Birthweight of the babies was within the 95th percentile.4 The infants were assessed every month for 6 months then every 3-4 months for at least 2 years. Two of the babies had long-term physiological jaundice and one had four episodes of respiratory infection during the first 8 months of life. Motor, adaptive, social, and language milestones in each baby were consistent with age, and no evidence of cartilage damage was found on regular clinical assessment up to 5 years. The manufacturers of ciprofloxacin (Bayer Pharma- ceuticals) have received reports on 130 women who have received the drug during pregnancy, in most during the first trimester when they did not know they were pregnant. No baby born to these women had any congenital abnormalities Table: Clinical features of seven patients with MDREF