Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-05-06T02:54:58.364Z Has data issue: false hasContentIssue false

Cortical Excitability in Amyotrophic Lateral Sclerosis: A Clue to Pathogenesis

Published online by Cambridge University Press:  18 September 2015

Andrew Eisen*
Affiliation:
Neuromuscular Diseases Unit, The Vancouver General Hospital and The University of BritishColumbia, Vancouver
Bhanu Pant
Affiliation:
Neuromuscular Diseases Unit, The Vancouver General Hospital and The University of BritishColumbia, Vancouver
Heather Stewart
Affiliation:
Neuromuscular Diseases Unit, The Vancouver General Hospital and The University of BritishColumbia, Vancouver
*
The Neuromuscular Diseases Unit, The Vancouver General Hospital, 855 West 12th Avenue, Vancouver, British Columbia, Canada V5Z 1M9
Rights & Permissions [Opens in a new window]

Abstract:

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Motor evoked potentials (MEPs) were recorded from selected non-wasted, non-denervated hand muscles in 40 patients with Amyotrophic Lateral Sclerosis (ALS) with both upper and lower motor neuron signs. In most the compound muscle action potential (CMAP) of the target muscle was normal. Compared to the control group, cortical threshold in ALS varied considerably and there was a significant (r2 = 0.702) inverse, exponential, correlation between cortical threshold and MEP/CMAP ratio. There was a linear correlation between threshold and disease duration (r2 = 0.66) so that early in the disease threshold was normal and later the motor cortex could not be stimulated. It is suggested that early in ALS normal threshold reflects glutamate-induced hyper-excitability of the corticomotoneuron. The findings lend support to the hypothesis that ALS is primarily a disease of the corticomotoneuron.

Type
Research Article
Copyright
Copyright © Canadian Neurological Sciences Federation 1993

References

1.Amassian, VE, Steward, M.Quick, GJ, Rosenthal, JC.Physiological basis of motor effects of a transient stimulus to cerebral cortex. Neurosurgery 1987; 20: 7493.CrossRefGoogle ScholarPubMed
2.Day, BL, Dressier, D, Maertens, de Noordhout A, Marsden, CD, et al.Electrical and magnetic stimulation of the human motor cortex: surface EMG and single motor unit responses. J Physiol (Lond) 1989; 412: 449473.CrossRefGoogle ScholarPubMed
3.Edgley, SA, Eyre, JA, Lemon, RN, Miller, S.Excitation of the corti-cospinal tract by electromagnetic and electrical stimulation of the scalp in the macaque monkey. J Physiol (Lond) 1990; 425: 301320.CrossRefGoogle ScholarPubMed
4.Porter, R.The cortico-motoneuronal component of the pyramidal tract: corticomotoneuronal connections and functions in primates. Brain Res Rev 1985; 357: 126.CrossRefGoogle Scholar
5.Porter, R.The corticomotoneuronal projections: synaptic events related to skilled movement. Proc Roy Soc Lond (Biol) 1987; 231: 147168.Google ScholarPubMed
6.Phillips, CG, Porter, R.Corticospinal Motoneurons. Academic Press, New York, 1977.Google Scholar
7.Davidoff, RA. The pyramidal tract. Neurology 1990; 40: 332339.CrossRefGoogle ScholarPubMed
8.Iwatsubo, T, Kuzuhara, S, Kanemitsu, A, et al.Corticofugal projections to the motor nuclei of the brainstem and spinal cord in humans. Neurology 1990; 40: 309312.CrossRefGoogle Scholar
9.Sillevis, Smitt PAE, de, Jong JMBV. Animal models of amyotrophic lateral sclerosis and spinal muscular atrophy. J Neurol Sci 1989; 91: 231258.Google Scholar
10.Eisen, A, Kim, S, Pant, B.Amyotrophic lateral sclerosis (ALS): a phylogenetic disease of the corticomotoneuron? Muscle Nerve 1992; 15: 219228.Google Scholar
11.Eisen, A, Calne, DB. Amyotrophic lateral sclerosis, Parkinson's disease and Alzheimer's disease: phylogenetic disorders of the human neocortex sharing many characteristics. Can J Neurol Sci 1992; 19(Suppl): 117120.CrossRefGoogle ScholarPubMed
12.Charcot, JM. Clinical Lectures on Diseases of the Nervous System. Vol. III (translated by Savill, T), The New Sydenham Society, London, 1889: 164182.Google Scholar
13.Keimahan, JA, Hudson, AJ. Changes in sizes of cortical and lower motor neurons in amyotrophic lateral sclerosis. Brain 1991; 114: 843853.Google Scholar
14.Cheney, PD, Fetz, EE. Comparable patterns of muscle facilitation evoked by individual corticomotoneuronal (CM) cells and by single intracortical microstimuli in primates: evidence of functional groups of CM cells. J Neurophysiol 1985; 53: 786804.CrossRefGoogle ScholarPubMed
15.Humphrey, DR. Representation of movements and muscles within the primate precentral motor cortex: historical and current perspectives. Fed Proc 1986; 45: 26872699.Google ScholarPubMed
16.Wiesendanger, M.Output organization of the rolandic cortex as revealed by electrical stimulation. In: Rossini, PM, Marsden, CD, eds. Non-Invasive Stimulation of Brain and Spinal Cord: Fundamentals and Clinical Applications. New York: Alan R. Liss, Inc 1988; 2335.Google Scholar
17.Homberg, V, Stephan, KM, Netz, J.Transcranial stimulation of motor cortex in upper motor neuron syndrome: its relation to motor deficit. Electroencephalogr Clin Neurophysiol 1991; 81: 377388.CrossRefGoogle ScholarPubMed
18.Rowland, LP. Ten central themes in a decade of ALS research. In: Rowland, LP, ed. Advances in Neurology, Vol. 56: Amyotrophic Lateral Sclerosis and Other Motor Neuron Diseases. Raven Press Ltd., 1991: 323.Google Scholar
19.Parry, GJ, Clarke, S.Multifocal acquired demyelinating neuropathy masquerading as motor neuron disease. Muscle Nerve 1988; 11: 103107.CrossRefGoogle ScholarPubMed
20.Pestronk, A.Invited review: motor neuronopathies, motor neuron disorders, and antiglycolipid antibodies. Muscle Nerve 1991; 14: 927936.Google Scholar
21.Daube, JR. Electrophysiolgical studies in the diagnosis and prognosis of motor neuron diseases. Neurol Clin 1985; 3: 473493.CrossRefGoogle Scholar
22.Eisen, A, Shtybel, W.Clinical experience with transcranial magnetic stimulation. Muscle Nerve 1990; 13: 9951011.CrossRefGoogle ScholarPubMed
23.Hufnagel, A, Elger, CE, Marx, W, Ising, A.Magnetic stimulation motor-evoked potentials in epilepsy: effects of the disease and anticonvulsant medications. Ann Neurol 1990; 28: 680686.CrossRefGoogle Scholar
24.Caramia, MD, Cicinelli, P, Paradiso, C, Marioenzi, R, et al.Excitability changes of muscular responses to magnetic brain stimulation in patients with central motor disorders. Electroencephalogr Clin Neurophysiol 1991; 81: 243250.CrossRefGoogle ScholarPubMed
25.Wassermann, EM, McSahane, LM, Hallett, M, Cohen, LG. Noninvasive mapping of muscle representations in human motor cortex. Electroencephalogr Clin Neurophysiol 1992; 85: 18.CrossRefGoogle ScholarPubMed
26.Hugon, J, Lubeau, M, Tabarard, F, Chazot, F, Vallat, JM, et al.Central motor conduction in motor neuron disease. Ann Neurol 1987; 22: 544546.CrossRefGoogle ScholarPubMed
27.Ingram, DA, Swash, M.Central motor conduction is abnormal in motor neuron disease. J Neurol Neurosurg Psychiatry 1987; 50: 159166.CrossRefGoogle ScholarPubMed
28.Schriefer, TN, Hess, CW, Mills, KR, Murray, NM. Central motor conduction studies in motor neuron disease using magnetic brain stimulation. Electroencephalogr Clin Neurophysiol 1989; 74: 431437.CrossRefGoogle ScholarPubMed
29.Eisen, A, Shytbel, W, Murphy, K, Hoirch, M.Cortical magnetic stimulation in amyotrophic lateral sclerosis. Muscle Nerve 1990; 13: 146151.CrossRefGoogle ScholarPubMed
30.Berardelli, A, Inghilleri, M, Cruccu, G, Mercuri, B, Manfredi, M.Electrical and magnetic transcranial stimulation in patients with corticospinal damage due to stroke or motor neuron disease. Electroencephalogr Clin Neurophysiol 1991; 81: 389396.CrossRefGoogle ScholarPubMed
31.Day, BL, Rothwell, JC, Thompson, PD, Dick, JP, Cowan, JMA, et al. 2. Multiple descending volleys. Brain 1987; 110: 11911209.CrossRefGoogle ScholarPubMed
32.Muller, K, Homberg, V, Lenard, HG.Magnetic stimulation of motor cortex and nerve roots in children. Maturation of corticomotoneuronal projections. Electroencephalogr Clin Neurophysiol 1991; 81: 6370.CrossRefGoogle Scholar
33.Carpenter, S, Karpati, G, Durham, H.Dendritic attrition precedes motor neuron death in amyotrophic lateral sclerosis (ALS). Neurology 1988; 38 (Suppl): 252.Google Scholar
34.Hess, CW, Mills, KR, Murray, NMF. Magnetic stimulation of the human brain: facilitation of motor responses by voluntary contraction of ipsilateral and contralateral muscles with additional observations in an amputee. Neurosci Lett 1986; 71: 235240.CrossRefGoogle Scholar
35.Rothwell, JC, Thompson, PD, Day, BL, Dick, JPR, Kachi, T, et al.Motor cortical stimulation in intact man. 1. General characteristics of EMG responses in different muscles. Brain 1987; 110: 11731190.CrossRefGoogle ScholarPubMed
36.Thompson, PD, Day, BL, Rothwell, JC, D, Dressier, Maertens, de Noordhout A, et al.Further observation on the facilitation of muscle responses to cortical stimulation by voluntary contraction. Electroencephalogr Clin Neurophysiol 1991; 81: 397402.CrossRefGoogle ScholarPubMed
37.Plaitakis, A.Glutamate dysfunction and selective motor neuron degeneration in amyotrophic lateral sclerosis: a hypothesis. Ann Neurol 1990; 28: 38.CrossRefGoogle ScholarPubMed
38.Young, AB, Penney, JB, Dauth, GW, et al.Glutamate or aspartate as a possible neurotransmitter of cerebral corticofugal fibers in the monkey. Neurology 1983; 33: 15131516.CrossRefGoogle ScholarPubMed
39.Shaw, PJ, Ince, PG, Johnson, M, EK, Perry, Candy, J.The quantitative autoradiographic distribution of [3H]MK-801 binding sites in normal human spinal cord. Brain Res 1991; 539: 164168.CrossRefGoogle ScholarPubMed
40.Malessa, S, Leigh, PN, Bertel, O, Sluga, E, Hornykeiwicz, O. Amyotrophic lateral sclerosis: glutamate dehydrogenase and transmitter amino acids in the spinal cord. J Neurol Neurosurg Psychiatry 1991; 54: 984988.CrossRefGoogle ScholarPubMed
41.Rothstein, JD, Martin, LJ, Kuncl, RW.Decreased glutamate transport by the brain and spinal cord in amyotrophic lateral sclerosis. N Engl J Med 1992; 326: 14641468.CrossRefGoogle ScholarPubMed