MarcGotkine, Department of Neurology, Hadassah University Hospital, P.O. Box 12000, Jerusalem 91120, Israelmarcgotkine@gmail.com
Oded Abramsky
Submitted December 04, 2006
We thank the authors for raising some important questions which
reiterate the importance of the discovery by Dr. Weinshenker's group of
the NMO-IgG and its value in defining patients with a distinct spectrum of
diseases.
We agree with Drs Weinshenker and Jacob, Dr. Ikeda et al and Dr.
Kister et al that the extensive longitudinal involvement of the spinal
cord with cord swelling is characteristic of the type of myelitis
occurring in patients with NMO-IgG. We also would point out that this
type of spinal cord lesion also occurs in patients with SLE. [10]
As SLE is a syndrome with clinical criteria we once again emphasize
that none of our patients had SLE (hence we defined the syndrome as a
"forme fruste") although we stand by our assertion that the neurological
involvement observed in some of our patients may be due to pathogenetic
mechanisms which also occur in SLE. [1]
Ikeda et al make a valid point regarding visual evoked potentials
(VEP). Although not fully detailed in our original paper these were normal
in patient 1 and abnormal in patients 3 and 4. Unfortunately patient 5 had
not performed a VEP test and was unavailable for further testing.
We are impressed by the close resemblance of clinical and laboratory
features between Dr. Ikeda's patient and our patient 1. The most
noteworthy difference is the clinical and electrophysiological evidence of
optic nerve dysfunction in Dr. Ikeda's patient whereas our patient 1 has
never suffered from visual symptoms and had normal visual evoked
potentials bilaterally. NMO-IgG has been reported in patients with MG with
classic NMO [4] but has not yet been documented in patients with MG and
isolated myelitis. Nevertheless, prior to the publication of our article
we sent serum from patient 1 (relapsing longitudinal myelitis) and patient
3 (relapsing localized myelitis) for NMO-IgG testing. Not surprisingly,
patient 1 (the patient discussed by Weinshenker and Jacob and Ikeda et
al) but not patient 3, tested positive for NMO-IgG.
Given that NMO occurs in patients with SLE [11] it is certainly
conceivable that the myelitis of SLE is closely related, if not part of
the NMO spectrum. As a corollary we hypothesize that systematic
investigation of SLE patients with longitudinal myelitis will reveal a
high proportion of patients with NMO-IgG.
We thank the authors for raising some important questions which reiterate the importance of the discovery by Dr. Weinshenker's group of the NMO-IgG and its value in defining patients with a distinct spectrum of diseases.
We agree with Drs Weinshenker and Jacob, Dr. Ikeda et al and Dr. Kister et al that the extensive longitudinal involvement of the spinal cord with cord swelling is characteristic of the type of myelitis occurring in patients with NMO-IgG. We also would point out that this type of spinal cord lesion also occurs in patients with SLE. [10]
As SLE is a syndrome with clinical criteria we once again emphasize that none of our patients had SLE (hence we defined the syndrome as a "forme fruste") although we stand by our assertion that the neurological involvement observed in some of our patients may be due to pathogenetic mechanisms which also occur in SLE. [1]
Ikeda et al make a valid point regarding visual evoked potentials (VEP). Although not fully detailed in our original paper these were normal in patient 1 and abnormal in patients 3 and 4. Unfortunately patient 5 had not performed a VEP test and was unavailable for further testing.
We are impressed by the close resemblance of clinical and laboratory features between Dr. Ikeda's patient and our patient 1. The most noteworthy difference is the clinical and electrophysiological evidence of optic nerve dysfunction in Dr. Ikeda's patient whereas our patient 1 has never suffered from visual symptoms and had normal visual evoked potentials bilaterally. NMO-IgG has been reported in patients with MG with classic NMO [4] but has not yet been documented in patients with MG and isolated myelitis. Nevertheless, prior to the publication of our article we sent serum from patient 1 (relapsing longitudinal myelitis) and patient 3 (relapsing localized myelitis) for NMO-IgG testing. Not surprisingly, patient 1 (the patient discussed by Weinshenker and Jacob and Ikeda et al) but not patient 3, tested positive for NMO-IgG.
Given that NMO occurs in patients with SLE [11] it is certainly conceivable that the myelitis of SLE is closely related, if not part of the NMO spectrum. As a corollary we hypothesize that systematic investigation of SLE patients with longitudinal myelitis will reveal a high proportion of patients with NMO-IgG.
References
10. Krishnan AV, Halmagyi GM. Acute transverse myelitis in SLE. Neurology 2004;62(11):2087-.
11. Jacobi C, Stingele K, Kretz R, et al. Neuromyelitis optica (Devic's syndrome) as first manifestation of systemic lupus erythematosus. Lupus 2006;15(2):107-109.
Disclosure: The authors report no conflicts of interest.