BACKGROUNDAmyotrophic lateral sclerosis (ALS) and some mimic disorders, such as distal-type cervical spondylotic amyotrophy (CSA), Hirayama disease (HD), and spinobulbar muscular atrophy (SBMA) may present with intrinsic hand muscle atrophy. This study aimed to investigate different patterns of small hand muscle involvement in ALS and some mimic disorders.

METHODSWe compared the abductor digiti minimi/abductor pollicis brevis (ADM/APB) compound muscle action potential (CMAP) ratios between 200 ALS patients, 95 patients with distal-type CSA, 88 HD patients, 43 SBMA patients, and 150 normal controls.

RESULTSThe ADM/APB CMAP amplitude ratio was significantly higher in the ALS patients (P < 0.001) than that in the normal controls. The ADM/APB CMAP amplitude ratio was significantly reduced in the patients with distal-type CSA (P < 0.001) and the HD patients (P < 0.001) compared with that in the normal controls. The patients with distal-type CSA had significantly lower APB CMAP amplitude than the HD patients (P = 0.004). The ADM/APB CMAP amplitude ratio was significantly lower in the HD patients (P < 0.001) than that in the patients with distal-type CSA. The ADM/APB CMAP amplitude ratio of the SBMA patients was similar to that of the normal controls (P = 0.862). An absent APB CMAP and an abnormally high ADM/APB CMAP amplitude ratio (≥4.5) were observed exclusively in the ALS patients.

CONCLUSIONSThe different patterns of small hand muscle atrophy between the ALS patients and the patients with mimic disorders presumably reflect distinct pathophysiological mechanisms underlying different disorders, and may aid in distinguishing between ALS and mimic disorders.

Action Potentials ; Adult ; Aged ; Amyotrophic Lateral Sclerosis ; pathology ; physiopathology ; Diagnosis, Differential ; Female ; Hand ; pathology ; Humans ; Male ; Middle Aged ; Muscle, Skeletal ; physiopathology ; Muscular Atrophy ; pathology ; physiopathology ; Retrospective Studies ; Spinal Muscular Atrophies of Childhood ; pathology ; Spondylosis ; pathology

We investigated the availability of motor unit number estimation (MUNE) as a quantitative method to assess the severity and clinical progression of amyotrophic lateral sclerosis (ALS). The 143 ALS patients were evaluated by statistical MUNE and the revised amyotrophic lateral sclerosis functional rating scale (ALSFRS-R). By using mean values of MUNE according to disease duration, regression equation between mean MUNE and disease duration was presented as a formula. The individual MUNE ratio was calculated by dividing individual MUNE value by mean MUNE value. All patients were classified into 2 groups (MUNE ratio <1 vs. MUNE ratio > or =1) according to the MUNE ratio. Comparison between the 2 groups revealed that the patients in MUNE ratio <1 group or MUNE ratio > or =1 group were respectively assigned to rapid progression or slow progression. We recommended informative mean values of MUNE and best regression equation in ALS patients according to disease duration. These values allow us to evaluate the severity and rapidity of progression in ALS.
Action Potentials/physiology ; Adult ; Age of Onset ; Aged ; Amyotrophic Lateral Sclerosis/*diagnosis/physiopathology ; Data Interpretation, Statistical ; Disease Progression ; Female ; Humans ; Male ; Middle Aged ; Motor Neurons/pathology/*physiology ; Muscle Fibers, Skeletal/physiology ; Severity of Illness Index

OBJECTIVETo study the activation changes of the brain in patients with amyotrophic lateral sclerosis (ALS) while executing sequential finger tapping movement using the method of blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI).

METHODSFifteen patients with definite or probable ALS and fifteen age and gender matched normal controls were enrolled. MRI was performed on a 3. 0 Tesla scanner with standard headcoil. The functional images were acquired using a gradient echo single shot echo planar imaging (EPI) sequence. All patients and normal subjects executed sequential finger tapping movement at the frequency of 1-2 Hz during a block-design motor task. Structural MRI was acquired using a three-dimensional fast spoiled gradient echo (3D-FSPGR) sequence. The fMRI data were analyzed by statistical parametric mapping (SPM).

RESULTSBilateral primary sensorimotor cortex (PSM), bilateral premotor area (PA), bilateral supplementary motor area (SMA), bilateral parietal region (PAR), contralateral inferior lateral premotor area (ILPA), and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task. The activation areas in bilateral PSM, bilateral PA, bilateral SMA, and ipsilateral cerebellum were significantly larger in ALS patients than those in normal controls (P < 0.05). Extra activation areas including ipsilateral ILPA, bilateral posterior limb of internal capsule, and contralateral cerebellum were only detected in ALS patients.

CONCLUSIONSSimilar activation areas are activated in ALS patients and normal subjects while executing the same motor task. The increased activation areas in ALS patients may represent neural reorganization, while the extra activation areas in ALS patients may indicate functional compensation.

Adult ; Amyotrophic Lateral Sclerosis ; diagnosis ; physiopathology ; Brain ; pathology ; Brain Mapping ; Female ; Fingers ; physiopathology ; Humans ; Magnetic Resonance Imaging ; instrumentation ; methods ; Male ; Middle Aged ; Movement ; physiology ; Neuronal Plasticity ; Oxygen ; blood