921
Complications developed
in the
patient with
the
highest IgM
anti-asialo-GM, titre, with fever, rigors, neutropenia, lymphadenopathy, and rash after completion of the first 5 days of IVIG. Further treatments were not given. Nonetheless, at 4 weeks he showed improved ulnar and median nerve conduction and increased muscle power in the affected hand. Another patient had a mild rash 3 days after completion of the first course of IVIG but not with subsequent treatments. Improvement in nerve conduction studies was documented in 3 patients, but an increase in muscle power was seen in only 2 of them. 2 patients with severe and focal neurological deficits in the arms showed no electrophysiological or myometric evidence of improvement after 4 months and have not received further IVIG. In 1 patient with severe left arm involvement whom we have now followed for 12 months, there was a pronounced improvement (from 1 to 2 Medical Research Council grades) during the first 3 months, followed by clinical deterioration during a 4 month gap in treatment. Recommencement of IVIG over 3 months has once again resulted in unequivocal improvement in power and some electrophysiological recovery; this patient did not have detectable anti-GM, antibodies. We have seen clinical or electrophysiological evidence of response in 3 of 5 patients with MMN, but in 1 of these a severe serum-sickness-like reaction has prevented further treatment. In some patients with MMN, progression of disease is very slow and deficits are severe and focal, both of which may confound assessment of response to therapy. Ganglioside antibodies have been shown experimentally to produce conduction block2 and are believed by many to be pathogenetic in MMN.’ However, many patients, including our most responsive ones, do not have detectable antibodies3 and therefore the diagnostic and pathogenetic role of the antibodies remains undefined. Although IVIG is effective in some cases, the respective roles of IVIG and cyclophospharnide4 remain to be established in MMN.
Department of Neurology, Sir Charles Gairdner Hospital, Nedlands 6009, Western Australia
A. G. KERMODE B. A. LAING W. M. CARROLL F. L. MASTAGLIA
1. Pestronk A, Chaudhry V, Feltman EL, et al. Lower motor neuron syndromes defined by patterns of weakness, nerve conduction abnormalities and high titres of
antiglycolipid antibodies. Ann Neurol 1990; 27: 316-26 M, Uncini A, Corbo M, et al. Experimental conduction block induced by serum from a patient with anti-GM1 antibodies Ann Neurol 1992; 31: 385-90. 3. Dyck PJ, Poduslo J, Bourque P, Curran G. Multifocal motor neuropathy. Neurology 1989; 39 (suppl 1) 391. 4. Feldman EL, Bromberg MB, Albers JW, Pestronk A Immunosuppressive treatment in multifocal motor neuropathy. Ann Neurol 1991; 30: 397-401. 2 Santoro
Disinfection of water
by sunlight
SIR,-Dr MacKenzie and colleagues (Aug 8, p 367)
are
right to
emphasise that conditions have to be right for solar sterilisation of cholera-contaminated water to be effective. These conditions may be summarised as follows. The containing vessel should be fully transparent. The bottle should be made of plastic (eg, polyethylene teraphthalate), not glass. Our experiments show that coke plastic (PET) transmits 90% of the incident long-wave ultraviolet lights, whereas coke glass transmits only 10%. Any cloudiness or opacity in the water diminishes the effectiveness of the rays. For this reason the bottle should be allowed to stand for 24 hours, being exposed early one morning and consumed the next day, having sedimented and then cooled overnight. Intensity of light is important because bactericidal properties will depend on the total energy content of the rays, which would be diminished by cloud and increased with altitude, as seen in the cholera experiment. Two different water sources were used in Latin America, one in Quito at a high altitude and the other at Santo Domingo at a low altitude. The poor bactericidal result at Santo Domingo may have been attributable to the cloudiness of the sample, rather than the altitude. Acra et al’ did their experiments on Escherichia coli in Beirut at sea level and found them effective. In our
Bactericidal effect of sunlight
on
Escherichia coli in water (105
organisms/ml). >
Mean
(range) neonatal Hb (g/dl)* Mean (range) neonatal PCV* Hb haemoglobin, *On day 1 of life
HUC blood volume:
Complications developed
in the
patient with
the
highest IgM
anti-asialo-GM, titre, with fever, rigors, neutropenia, lymphadenopathy, and rash after completion of the first 5 days of IVIG. Further treatments were not given. Nonetheless, at 4 weeks he showed improved ulnar and median nerve conduction and increased muscle power in the affected hand. Another patient had a mild rash 3 days after completion of the first course of IVIG but not with subsequent treatments. Improvement in nerve conduction studies was documented in 3 patients, but an increase in muscle power was seen in only 2 of them. 2 patients with severe and focal neurological deficits in the arms showed no electrophysiological or myometric evidence of improvement after 4 months and have not received further IVIG. In 1 patient with severe left arm involvement whom we have now followed for 12 months, there was a pronounced improvement (from 1 to 2 Medical Research Council grades) during the first 3 months, followed by clinical deterioration during a 4 month gap in treatment. Recommencement of IVIG over 3 months has once again resulted in unequivocal improvement in power and some electrophysiological recovery; this patient did not have detectable anti-GM, antibodies. We have seen clinical or electrophysiological evidence of response in 3 of 5 patients with MMN, but in 1 of these a severe serum-sickness-like reaction has prevented further treatment. In some patients with MMN, progression of disease is very slow and deficits are severe and focal, both of which may confound assessment of response to therapy. Ganglioside antibodies have been shown experimentally to produce conduction block2 and are believed by many to be pathogenetic in MMN.’ However, many patients, including our most responsive ones, do not have detectable antibodies3 and therefore the diagnostic and pathogenetic role of the antibodies remains undefined. Although IVIG is effective in some cases, the respective roles of IVIG and cyclophospharnide4 remain to be established in MMN.
Department of Neurology, Sir Charles Gairdner Hospital, Nedlands 6009, Western Australia
A. G. KERMODE B. A. LAING W. M. CARROLL F. L. MASTAGLIA
1. Pestronk A, Chaudhry V, Feltman EL, et al. Lower motor neuron syndromes defined by patterns of weakness, nerve conduction abnormalities and high titres of
antiglycolipid antibodies. Ann Neurol 1990; 27: 316-26 M, Uncini A, Corbo M, et al. Experimental conduction block induced by serum from a patient with anti-GM1 antibodies Ann Neurol 1992; 31: 385-90. 3. Dyck PJ, Poduslo J, Bourque P, Curran G. Multifocal motor neuropathy. Neurology 1989; 39 (suppl 1) 391. 4. Feldman EL, Bromberg MB, Albers JW, Pestronk A Immunosuppressive treatment in multifocal motor neuropathy. Ann Neurol 1991; 30: 397-401. 2 Santoro
Disinfection of water
by sunlight
SIR,-Dr MacKenzie and colleagues (Aug 8, p 367)
are
right to
emphasise that conditions have to be right for solar sterilisation of cholera-contaminated water to be effective. These conditions may be summarised as follows. The containing vessel should be fully transparent. The bottle should be made of plastic (eg, polyethylene teraphthalate), not glass. Our experiments show that coke plastic (PET) transmits 90% of the incident long-wave ultraviolet lights, whereas coke glass transmits only 10%. Any cloudiness or opacity in the water diminishes the effectiveness of the rays. For this reason the bottle should be allowed to stand for 24 hours, being exposed early one morning and consumed the next day, having sedimented and then cooled overnight. Intensity of light is important because bactericidal properties will depend on the total energy content of the rays, which would be diminished by cloud and increased with altitude, as seen in the cholera experiment. Two different water sources were used in Latin America, one in Quito at a high altitude and the other at Santo Domingo at a low altitude. The poor bactericidal result at Santo Domingo may have been attributable to the cloudiness of the sample, rather than the altitude. Acra et al’ did their experiments on Escherichia coli in Beirut at sea level and found them effective. In our
Bactericidal effect of sunlight
on
Escherichia coli in water (105
organisms/ml). >
Mean
(range) neonatal Hb (g/dl)* Mean (range) neonatal PCV* Hb haemoglobin, *On day 1 of life
HUC blood volume:
