Julia Birchenall1, Maxime Térémetz2, Pauline Roca1, Jean-Charles Lamy3, Catherine Oppenheim1, Marc A Maier4, Jean-Louis Mas1, Catherine Lamy1, Jean-Claude Baron1, Påvel G Lindberg5. 1. Centre de psychiatrie et neurosciences, Inserm U894, hôpital Sainte-Anne, université Paris Descartes, 75014 Paris, France. 2. Centre de psychiatrie et neurosciences, Inserm U894, hôpital Sainte-Anne, université Paris Descartes, 75014 Paris, France; FR3636 CNRS, université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France. 3. Inserm U 1127, CNRS UMR 7225, Sorbonne universités, UPMC université Paris 06 UMR S 1127, institut du cerveau et de la Moelle épinière, ICM, centre de neuro-imagerie de recherche (CENIR), 75013 Paris, France. 4. FR3636 CNRS, université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France. 5. Centre de psychiatrie et neurosciences, Inserm U894, hôpital Sainte-Anne, université Paris Descartes, 75014 Paris, France; FR3636 CNRS, université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France. Electronic address: pavel.lindberg@inserm.fr.
Abstract
OBJECTIVES: In this longitudinal pilot study, we investigated how manual dexterity recovery was related to corticospinal tract (CST) injury and excitability, in six patients undergoing conventional rehabilitation. METHODS: Key components of manual dexterity, namely finger force control, finger tapping rate and independence of finger movements, were quantified. Structural MRI was obtained to calculate CST lesion load. CST excitability was assessed by measuring rest motor threshold (RMT) and the amplitude of motor evoked potentials (MEPs) using transcranial magnetic stimulation (TMS). Measurements were obtained at two weeks, three and six months post-stroke. RESULTS: At six months post-stroke, complete recovery of hand gross motor impairment (i.e., maximal Fugl-Meyer score for hand) had occurred in three patients and four patients had recovered ability to accurately control finger force. However, tapping rate and independence of finger movements remained impaired in all six patients at six months. Recovery in hand gross motor impairment and finger force control occurred in patients with smaller CST lesion load and almost complete recovery of CST excitability, although RMT or MEP size remained slightly altered in the stroke-affected hemisphere compared to the unaffected hemisphere. The two patients with poorest recovery showed persistent absence of MEPs and greatest structural injury to CST. DISCUSSION: The findings support good motor recovery being overall correlated with smaller CST lesion, and with almost complete recovery of CST excitability. However, impairment of manual dexterity persisted despite recovery in gross hand movements and grasping abilities, suggesting involvement of additional brain structures for fine manual tasks.
OBJECTIVES: In this longitudinal pilot study, we investigated how manual dexterity recovery was related to corticospinal tract (CST) injury and excitability, in six patients undergoing conventional rehabilitation. METHODS: Key components of manual dexterity, namely finger force control, finger tapping rate and independence of finger movements, were quantified. Structural MRI was obtained to calculate CST lesion load. CST excitability was assessed by measuring rest motor threshold (RMT) and the amplitude of motor evoked potentials (MEPs) using transcranial magnetic stimulation (TMS). Measurements were obtained at two weeks, three and six months post-stroke. RESULTS: At six months post-stroke, complete recovery of hand gross motor impairment (i.e., maximal Fugl-Meyer score for hand) had occurred in three patients and four patients had recovered ability to accurately control finger force. However, tapping rate and independence of finger movements remained impaired in all six patients at six months. Recovery in hand gross motor impairment and finger force control occurred in patients with smaller CST lesion load and almost complete recovery of CST excitability, although RMT or MEP size remained slightly altered in the stroke-affected hemisphere compared to the unaffected hemisphere. The two patients with poorest recovery showed persistent absence of MEPs and greatest structural injury to CST. DISCUSSION: The findings support good motor recovery being overall correlated with smaller CST lesion, and with almost complete recovery of CST excitability. However, impairment of manual dexterity persisted despite recovery in gross hand movements and grasping abilities, suggesting involvement of additional brain structures for fine manual tasks.
Authors: Helena Hybbinette; Ellika Schalling; Jeanette Plantin; Catharina Nygren-Deboussard; Marika Schütz; Per Östberg; Påvel G Lindberg Journal: Front Neurol Date: 2021-03-31 Impact factor: 4.003