FUNCTIONAL MAGNETIC RESONANCE IMAGING OF BRAIN MOTOR AREAS IN HEREDITARY SPASTIC PARAPARESIS PATIENTS
Abstract
Background. Hereditary spastic paraparesis (HSP) is a heterogeneous group of disorders with corticospinal tract (CST) degeneration in which the main clinical feature is progressive bilateral lower limb spasticity. Functional imaging studies in patients with CST involvement have shown reorganization of motor cortex. Our study investigates functional adaptation of motor brain areas in HSP patients.
Methods. Nine HSP patients and 10 healthy subjects were studied. Functional magnetic resonance imaging (fMRI) was used to measure activation of cortical motor areas and cerebellum during finger tapping. Image analysis was performed using general linear model and regions-of-interest (ROI) based approach. Laterality indexes (LI) were calculated for cortical and cerebellar ROIs.
Results. Comparing patients and controls at the tapping rate of 1.8 Hz, there was higher fMRI activation in patients’ ipsilateral lateral sensorimotor (iLSM) area and contralateral cerebellum (cCRB) compared to controls, while controls showed higher activation in cLSM and iCRB. LI was significantly lower in patients’ LSM and CRB. Comparing patients and controls at 80% of their maximum tapping rates, the activation of cCRB was higher in patients, while cLSM and iCRB were higher in controls. LSM LI didn’t differ significantly between the HSP and control groups, but the cerebellar LI was significantly lower in patients.
Conclusions. Our results suggest functional adaptation of the motor areas in HSP patients. The findings may reflect a combination of functional reorganization and compensatory brain activation at increased relative effort. Lower cLSM and iCRB activation in patients compared to controls might reflect the disorder of motor system in HSP.
Downloads
References
Fink JK. Hereditary spastic paraplegia. Neurol Clin N Am 2002; 20: 711–26.
Fink JK. The hereditary spastic paraplegias: nine genes and counting. Arch Neurol 2003; 60: 1045–9.
Fortini D, Cricchi F, Di Fabio R et al. Current insights into familial spastic paraparesis: new advances in an old disease. Funct Neurol 2003; 18: 43–9.
Scheuer KH, Nielsen JE, Krabbe K, Sřrensen SA, Paulson OB, Law I. Modified motor activation in autosomal dominant pure spastic paraplegia (ADPSP) using PET. Neuroimage 2001; 13: S834.
Kew JJ, Leigh PN, Playford ED et al. Cortical function in amyotrophic lateral sclerosis. A positron emission tomography study. Brain 1993; 116: 655–80.
Reddy H, Narayanan S, Woolrich M et al. Functional brain reorganization for hand movement in patients with multiple sclerosis: defining distinct effects of injury and disability. Brain 2002; 125: 2646–57.
Curt A, Alkadhi H, Crelier GR, Boendermaker SH, Hepp-Reymond MC, Kollias SS. Changes of non-affected upper limb cortical representation in paraplegic patients as assessed by fMRI. Brain 2002; 125: 2567–78.
Sach M, Winkler G, Glauche V et al. Degeneration of corticospinal tract fibers in patients with hereditary spastic paraplegia compared to patients with amyotrophic lateral sclerosis in diffusion tensor imaging (abstract). Presented at the 9th International Conference on Functional Mapping of the Human Brain, June 19-22, 2003, New York, NY. Available on CD-Rom in NeuroImage, Vol. 19, No. 2.
Schulte T, Miterski B, Bornke C, Przuntek H, Epplen JT, Schols L. Neurophysiological findings in SPG4 patients differ from other types of spastic paraplegia. Neurology 2003; 60: 1529–32.
Bönsch D, Schwindt A, Navratil P et al. Motor system abnormalities in hereditary spastic paraparesis type 4 (SPG4) depend on the type of mutation in the spastin gene. J Neurol Neurosurg Psychiatry 2003; 74: 1109–12.
The Author transfers to the Publisher (Zdravniški vestnik/Slovenian Medical Journal) all economic copyrights following form Article 22 of the Slovene Copyright and Related Rights Act (ZASP), including the right of reproduction, the right of distribution, the rental right, the right of public performance, the right of public transmission, the right of public communication by means of phonograms and videograms, the right of public presentation, the right of broadcasting, the right of rebroadcasting, the right of secondary broadcasting, the right of communication to the public, the right of transformation, the right of audiovisual adaptation and all other rights of the author according to ZASP.
The aforementioned rights are transferred non-exclusively, for an unlimited number of editions, for the term of the statutory
The Author can make use of his work himself or transfer subjective rights to others only after 3 months from date of first publishing in the journal Zdravniški vestnik/Slovenian Medical Journal.
The Publisher (Zdravniški vestnik/Slovenian Medical Journal) has the right to transfer the rights, acquired parties without explicit consent of the Author.
The Author consents that the Article be published under the Creative Commons BY-NC 4.0 (attribution-non-commercial) or comparable licence.