Occurrence of CNS demyelinating disease in patients with myasthenia gravis
KenIkeda, Department of Neurology, PL Tokyo Health Care Center, 16-1, Kamiyamacho, Shibuyaku, Tokyo, 150-0047, Japankeni@pl-tokyo-kenkan.gr.jp
Yo Araki, and Yasuo Iwasaki.
Submitted December 04, 2006
We read with great interest the article by Gotkine et
al [1]
concerning occurrence of CNSDD and myasthenia gravis (MG). We also
encountered one patient with recurrent myelitis among 325 patients with
MG.
A 53-year-old woman was diagnosed as MG at age 29. Thymectomy
was performed at age 30 years and the pathologic finding revealed
hyperplasia. After she was treated with pyridostigmine and prednisolone
until age 42 years, MG was remitted completely without medication. Three
years later, she developed weakness and dysesthesisa in the upper limbs.
Cervical MRI showed T2-hyperintensity signal areas in the C2-6 segments
with enhancement. Methylprednisolone treatment improved motor and
sensory deficits without sequences. She experienced paresthesia ascending
from the lower limbs to body and upper limbs and painful tonic seizures in the upper limbs at age 51. Neurological examination showed
paresthesia and hyperreflexia in the four extremities and Lhermitte's
sign was
presented.
Immunological analyses showed negative acetylcholine receptor
antibodies and increased anti-nuclear antibodies. Brain MRI was normal.
Spinal MRI disclosed T2-hyperintensity signal areas in the C3-T1 segments
with ring-shaped enhancement. On visual evoked potentials, P100 latency
was delayed (115 msec in the right and 118 msec in the left). Two years
later, optic neuritis occurred. The final diagnosis of neuromyelitis
optica
(NMO) was made.
According to recent diagnostic criteria for NMO, [6] the features of spinal
MRI
reveal longitudinally extensive cord lesions more than three segments in our
and
four patients of Gotkine et al. [1] Those pathognomic distribution of spinal
lesions suggest a possibility of NMO. Gotkine et al [1] describe that
prolonged
visual evoked potentials in Patient 4. The first question is whether
visual
evoked potentials are performed in Patient 1, 3 and 5. The first question
is
whether visual evoked potentials are performed in the other four patients. We
would
like to know serum NMO-IgG antibodies in Patient 1 and 5 who have no
lesions on brain MRI. How is the possibility of NMO in those patients? NMO
is
associated in MG patients after thymectomy. [4,7] Besides NMO, recurrent
myelitis without optic neuritis could contribute to common immunological
mechanism as a subgroup of CNSDD in thymectomized MG patients.
References
6. Wingerchuk DM, Lennon VA, Pittock SJ, Lucchinetti CF, Weinshenker BG.
Revised diagnostic criteria for neuromyelitis optica. Neurology 2006; 66:
1485-1489.
7. Furukawa Y, Yoshikawa H, Yachie A, Yamada M. Neuromyelitis optica
associated with myasthenia gravis: characteristic phenotype in Japanese
population. Eur J Neurol 2006; 13: 655-658.
Disclosure: The authors report no conflicts of interest.
We read with great interest the article by Gotkine et al [1] concerning occurrence of CNSDD and myasthenia gravis (MG). We also encountered one patient with recurrent myelitis among 325 patients with MG.
A 53-year-old woman was diagnosed as MG at age 29. Thymectomy was performed at age 30 years and the pathologic finding revealed hyperplasia. After she was treated with pyridostigmine and prednisolone until age 42 years, MG was remitted completely without medication. Three years later, she developed weakness and dysesthesisa in the upper limbs. Cervical MRI showed T2-hyperintensity signal areas in the C2-6 segments with enhancement. Methylprednisolone treatment improved motor and sensory deficits without sequences. She experienced paresthesia ascending from the lower limbs to body and upper limbs and painful tonic seizures in the upper limbs at age 51. Neurological examination showed paresthesia and hyperreflexia in the four extremities and Lhermitte's sign was presented.
Immunological analyses showed negative acetylcholine receptor antibodies and increased anti-nuclear antibodies. Brain MRI was normal. Spinal MRI disclosed T2-hyperintensity signal areas in the C3-T1 segments with ring-shaped enhancement. On visual evoked potentials, P100 latency was delayed (115 msec in the right and 118 msec in the left). Two years later, optic neuritis occurred. The final diagnosis of neuromyelitis optica (NMO) was made.
According to recent diagnostic criteria for NMO, [6] the features of spinal MRI reveal longitudinally extensive cord lesions more than three segments in our and four patients of Gotkine et al. [1] Those pathognomic distribution of spinal lesions suggest a possibility of NMO. Gotkine et al [1] describe that prolonged visual evoked potentials in Patient 4. The first question is whether visual evoked potentials are performed in Patient 1, 3 and 5. The first question is whether visual evoked potentials are performed in the other four patients. We would like to know serum NMO-IgG antibodies in Patient 1 and 5 who have no lesions on brain MRI. How is the possibility of NMO in those patients? NMO is associated in MG patients after thymectomy. [4,7] Besides NMO, recurrent myelitis without optic neuritis could contribute to common immunological mechanism as a subgroup of CNSDD in thymectomized MG patients.
References
6. Wingerchuk DM, Lennon VA, Pittock SJ, Lucchinetti CF, Weinshenker BG. Revised diagnostic criteria for neuromyelitis optica. Neurology 2006; 66: 1485-1489.
7. Furukawa Y, Yoshikawa H, Yachie A, Yamada M. Neuromyelitis optica associated with myasthenia gravis: characteristic phenotype in Japanese population. Eur J Neurol 2006; 13: 655-658.
Disclosure: The authors report no conflicts of interest.