Split Hand Sign Research Articles

Nerve conduction study on the split-hand plus index in Amyotrophic lateral sclerosis: correlations with lower motor neuron impairment.

In the arms of patients with Amyotrophic lateral sclerosis (ALS) two peculiar patterns of dissociated muscular atrophy have been described: the split-hand sign (with predominant atrophy of the lateral aspect of the hand, compared to hypothenar eminence) and the split-hand-plus sign (SHPS), a predominant abductor pollicis brevis (ABP) atrophy with sparing of flexor pollicis longus (FPL). In this case-control study, we evaluated the diagnostic utility of a neurophysiological indicator of SHPS and assessed its association with clinical features. We prospectively studied 59 incident ALS patients, 61 patients with ALS-mimic disorders (OND) and 61 non-neurological controls (NNCs). ABP and FPL compound muscle action potentials (CMAP) amplitudes were obtained by supramaximal stimulation of median nerve at elbow. Split-hand plus index (SHPI) was calculated according to the formula: APB-CMAP/FPL-CMAP. SHPI was significantly lower in ALS compared to OND patients and NNCs (p < 0.0001). SHPI value < 1 was observed in 2% of NNCs and 9% of OND patients and demonstrated an accuracy of 71% in differentiating ALS from OND and an accuracy of 74% in differentiating ALS from NNC. SHPI was associated with higher LMN score, and higher disease severity as quantified by the ALSFRS-r. Our results indicate that SHPI is a reliable indicator to distinguish ALS patients from ONDs and NNCs. SHPI was significantly associated to the degree of lower motor neuron impairment but showed no association with upper motoneuron impairment.

N°199 – Reverse split hand sign in Spinal Muscular Atrophy and Hirayama disease: A comparative clinico-electrophysiological study

N°199 – Reverse split hand sign in Spinal Muscular Atrophy and Hirayama disease: A comparative clinico-electrophysiological study

Split-hand index for amyotrophic lateral sclerosis diagnosis: A frequentist and Bayesian meta-analysis

ObjectivePreferential wasting of the thenar muscles, the split-hand sign, may be used for early diagnosis of amyotrophic lateral sclerosis (ALS). MethodsElectronic databases were searched for studies assessing the split-hand index (SHI) and the compound muscle action potential (CMAP) amplitudes of abductor pollicis brevis (APB), first dorsal interosseous (FDI), and abductor digiti minimi (ADM). The SHI was obtained by multiplying CMAP amplitudes of APB and FDI and dividing the product by the CMAP amplitude of ADM. The Bayesian analysis was used for validation. ResultsIn total, 17 studies and 1635 patients were included. Our meta-analysis revealed that ALS patients had significantly decreased SHI (standardized mean difference [SMD], −1.60, P < 0.001), CMAP of the APB (SMD, −1.67, P < 0.001), FDI (SMD, −1.12, P < 0.001), and ADM (SMD, −1.09, P < 0.001). The binormal receiver operating characteristic curve analysis showed a threshold of < 7.4 for SHI, and cutoff values of < 6.4 mV for APB and < 8.4 mV for FDI, respectively. The Bayesian analysis validated decreased SHI in ALS patients (posterior mean difference of − 5.91). ConclusionsAn SHI of < 7.4 can be used facilitating earlier diagnosis of ALS. SignificanceSHI can be used as a standard neurophysiological biomarker for early diagnosis.

Amyotrofik lateral skleroz erken tanısında sinir iletim çalışmaları ve ayrık el bulgusunun önemi

Aim: The heterogeneity of the Amyotrophic Lateral Sclerosis (ALS) clinical phenotypes leads to difficulties in early diagnosis. The ‘split hand’ sign is defined as the thenar muscles that are more prominently affected by hypothenar. In this study, the results of the initial nerve conduction study of the patients were compared with those of the controls in order to increase the findings supporting early diagnosis.&#x0D; Material and Method: Seventy-five patients who were diagnosed with ALS in our clinic were included in the study. The initial ENMG findings of the patients were compared with those of 70 healthy controls: Distal motor latency (DML), the compound muscle action potential (CMAP) amplitude, velocity in the motor conduction of median, ulnar, peroneal and tibial nerves; distal latency, amplitude, velocity in sensorial conduction were evaluated. Ulnar/median DML and ulnar/median CMAP amplitude ratios were examined.&#x0D; Results: In ALS group, DMLs of the median, ulnar, peroneal, and tibial nerves were significantly longer, and CMAP amplitudes were significantly smaller than those of the controls. The sensory conductions of the median, ulnar, and sural nerves were not statistically different between the groups. The ulnar/median DML ratio of the patients was lower than the ratio of controls (0.73/0.80;p=0.003); while the ulnar/median CMAP amplitude ratio was greater (1.40/1.11; p=0.002).&#x0D; Conclusion: Prolonged DML and reduced amplitudes were observed in the motor nerve conduction of ALS patients in the early period. The results of the present study also support the presence of split-hand phenomenon even in early period of limb-onset ALS (both upper and lower). These findings suggest that nerve conduction studies and electrophysiologically detected split-hand sign are important clues for the early diagnosis of ALS in case of heterogeneous clinical phenotype.

HP32: Split foot sign in amyotrophic lateral sclerosis (ALS)

To evaluate the pattern of the extensor digitorum brevis (EDB), the abductor hallucis (AH) muscles’ involvement in ALS and Abductor digiti minimi (ADM) looking for the possibility of having split foot sign like split hand one. Background: The muscle patterns involved in amyotrophic lateral sclerosis (ALS) remains controversial. split leg and split hand signs were assessed previously. However; foot muscles involvement could be not equal in ALS like in case of split hand sign with preference for lateral hand muscles. Methods: We recruited 11 patients with ALS and 12 healthy controls. Compound muscle action potentials (CMAPs) were recorded over the EDB, ADM and AH muscles in all subjects. EDB/AH and ADM/AH ratios were obtained and compared between patients and controls. Results: The EDB/AH and ADM/AH CMAP amplitude ratio were significantly reduced in patients with ALS (0.26 ± 0.16, P = 0.001) and (0.27 ± 0.10, p = 0.001) respectively. These findings indicate a greater loss of lower motor neurons innervating the EDB and ADM and dysfunction of spinal motor neurons innervating these muscles. The EDB/AH and ADM/AH CMAP ratios reliably differentiated patients from HCs, with AUCs of 0.42 (95% CI 0.00-0.9) and 0.41 (95% CI 0.00–0.95), sensitivities of 78%, and specificities of 100% for both with cut-off ratios of 0.12 and 0.15 respectively. Conclusions: These results suggest preferential EDB and ADM compared to AH involvement in ALS. The EDB/AH and ADM/AH CMAP ratios robustly differentiated patients with ALS from HCs, which might facilitate an earlier identification of ALS patients.

Split phenomenon of antagonistic muscle groups in amyotrophic lateral sclerosis: relative preservation of flexor muscles

ABSTRACT Objective: In addition to the split hand sign, other split phenomena of different muscles also exist in amyotrophic lateral sclerosis (ALS). We analyzed the incidence of split phenomena in multiple antagonistic muscle groups in ALS patients and explored whether clinical factors affected their occurrence. Methods: 618 ALS patients were included from a single ALS center. Muscle strength in upper and lower limbs was evaluated using the modified Medical Research Council (MRC) scoring system (range from 1 to 13). Split phenomena between different antagonistic muscle groups were summarized, and the correlations with clinical factors were analyzed. Results: Split phenomena were detected in 22.3% antagonistic muscles for flexion and extension of the elbow, 11.9% for the wrist, 23.9% for fingers, 18.2% for the ankle, and 14.7% for toes. These manifestations were characterized by preferential wasting of the elbow, wrist, and finger extensor muscles compared with the flexor muscles, and the ankle and toe dorsiflexor muscles compared with the plantar flexor muscles. The presence of muscle wasting was more common when the muscle strength was stronger than a modified MRC grade 6. No definite correlation was found between split phenomena and clinical factors, including age-at-onset, gender, disease duration, the region of onset, and pyramidal tract damage. Discussion: Split phenomena of antagonistic muscle groups widely exist in ALS patients. No definitive and consistent clinical factors were observed that affected the occurrence of these phenomena.

Split-hand index in amyotrophic lateral sclerosis: an F-wave study

Objective: Split-hand sign is a useful clinical and electrophysiological feature in the diagnosis of amyotrophic lateral sclerosis (ALS). We proposed a novel split-hand index (SI) using F-wave persistence (FP) and assessed its diagnostic utility in ALS. Methods: Eighty-three consecutive ALS patients were recruited, and 50 healthy, age-, and height-matched volunteers were used as a control group. Compound muscle action potentials (CMAP) and FP were recorded from the abductor pollicis brevis (APB), first dorsal interosseous (FDI), and the abductor digiti minimi (ADM) muscles. The SI derived from FP was calculated using the following formula: SIFP = (FPAPB ×FPFDI)/FPADM. The sensitivity and specificity of SIFP and SICMAP in differentiating ALS from healthy controls (HCs) were derived from receiver-operating characteristic (ROC) curve analysis. Results: Both SIFP and SICMAP were significantly reduced in ALS patients. The ROC curve analysis indicated that both SIFP and SICMAP reliably differentiated ALS from HCs [0.92 (95% CI: 0.88–0.95); 0.86 (95% CI: 0.82–0.91)], but SIFP showed better diagnostic accuracy than SICMAP (p = 0.04), with a high sensitivity (81.2%) and specificity (97%). In subgroup analyses, SIFP appeared to be a better variable than SICMAP for differentiation of ALS patients with normal CMAP from HCs, with an area under the curve of 0.87 (95% CI: 0.80–0.93), sensitivity of 69.4%, and specificity of 94%. Conclusion: The SIFP reliably distinguished ALS patients from HCs and may be more sensitive for determining the split-hand pattern of ALS than SICMAP, particularly in the early stage of the disease.

Relative preservation of triceps over biceps strength in upper limb-onset ALS: the ‘split elbow’

ObjectiveAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the motor system. The split hand sign in ALS refers to observed preferential weakness of the lateral hand muscles, which is...

Role Of spinal mechanisms in the pathophysiology of the split hand sign in amyotrophic lateral sclerosis

Role Of spinal mechanisms in the pathophysiology of the split hand sign in amyotrophic lateral sclerosis

4. Median/ulnar nerve ultrasound cross-sectional area ratio in ALS

Background It has been shown that hand muscle wasting in amyotrophic lateral sclerosis (ALS) preferentially affects the thenar muscles, with relative sparing of the hypothenar muscles. This so-called “split-hand” is clinical sign that can be used to differentiate ALS from mimic disorders, and is thought to be caused by a difference in nerve excitability between median and ulnar nerve. The split-hand phenomenon has been largely discussed in regard to neurophysiological finding, but no studies performed comparing median and ulnar nerve size using ultrasound. We therefore sought to compare nerve size between the median and ulnar nerves in ALS using ultrasound in order to determine whether this may give further insight into the split-hand phenomenon. Objective To identify whether nerve ultrasound results might reflect the clinical split-hand sign in ALS patients and whether these findings can be used to differentiate ALS from other neuromuscular disorders. Methods Ultrasound was used to image both the median and ulnar nerves of 98 patients with ALS and 82 patients with other neuromuscular disorders (non-ALS). The nerve cross-sectional area (CSA) was measured at the wrist, the forearm, and the upper arm bilaterally. Nerve CSA values and median/ulnar nerve CSA ratios were compared at different locations between the two groups. Result Both the median and ulnar nerve CSA values were smaller in the ALS group than in the non-ALS group, except for the median nerve at the wrist. The median/ulnar nerve CSA ratio was comparatively decreased in the upper arm segment. There was a significant difference between the two groups at the wrist on the left side and at upper arm on the right side (Left wrist (IQR) ALS: 2.00 (1.67, 2.33) vs non-ALS: 1.63 (1.35, 2.18) p = 0.003, Right upper arm (IQR) ALS: 1.29 (1.12, 1.50) vs non-ALS: 1.37 (1.16, 1.69) p = 0.003). Conclusion We observed that the median/ulnar nerve CSA ratio was decreased in ALS patient at the upper arm segment. Overall, these findings suggest that there is preferential involvement of the median nerve compared to the ulnar nerve in ALS, which is consistent with the clinical findings of the split hand in these patients. This adds further support to the involvement of peripheral mechanisms underlying this phenomenon. Therefore, ultrasound may be a useful non-invasive tool to objectively detecting changes. Further studies assessing cortical contribution to the clinical and ultrasound findings are warranted to elucidate this pathology further.

Split-hand phenomenon in amyotrophic lateral sclerosis: A motor unit number index study.

The split-hand phenomenon refers to preferential wasting of the thenar muscles with relative sparing of the hypothenar muscles in amyotrophic lateral sclerosis (ALS). We compared the split-hand index (SI) calculated from the compound muscle action potential (CMAP; SICMAP ) with that calculated from the motor unit number index (MUNIX; SIMUNIX ). We performed MUNIX on the abductor policis brevis (APB), first dorsal interosseous (FDI), and abductor digiti minimi (ADM) muscles of 39 ALS patients and 40 age-matched, healthy controls. SI is derived by multiplying the CMAP (or MUNIX) recorded over the APB and FDI and dividing by the CMAP (or MUNIX) recorded over the ADM. Receiver-operating characteristic curve analysis revealed good diagnostic accuracy for both indices, but better performance of SIMUNIX than SICMAP . SIMUNIX and SICMAP were useful in differentiating ALS patients from healthy controls. SIMUNIX appears to be a better electrophysiological marker than SICMAP for the split-hand sign of ALS. Muscle Nerve 53: 885-888, 2016.

Relative preservation of finger flexion in amyotrophic lateral sclerosis

A characteristic pattern of intrinsic hand muscle involvement—known as the split hand sign—is typical of ALS; differential involvement of forearm muscles has not been examined systematically.After observing that finger-flexion was often preserved in ALS, despite severe weakness of finger-extension, we assessed the relative involvement of these two muscle groups in a cohort of patients with ALS.We found finger-flexion to be relatively preserved, when compared with finger-extension, in patients with ALS. In many cases finger-flexion is only minimally affected, even when finger-extension is totally paralyzed.The reasons for this predilection are unclear, but may be similar to those underlying the split-hand sign. Nevertheless, the discrepancy may provide another useful clinical clue in patients presenting with distal upper-limb weakness.

P544: Cortical hyperexcitability of the thenar group of intrinsic hand muscles may contribute to the split-hand sign in ALS

Objective Preferential wasting of the thenar group of intrinsic hand muscles including the abductor pollicis brevis (APB) and first dorsal interosseous (FDI) termed the split-hand sign, has been described as a specific feature of Amyotrophic Lateral Sclerosis (ALS). Greater corticomotorneuronal input to the thenar intrinsic hand muscles has been proposed as one of the pathophysiological mechanisms underlying the split hand sign and consequently difference in cortical excitability between the thenar and hypothenar intrinsic hand muscles was assessed in the present study, in a group of ALS patients and age matched healthy controls. Methods Cortical excitability was recorded using the threshold tracking transcranial magnetic stimulation (TMS) technique from the APB, FDI and abductor digiti minimi (ADM) muscles in 26 Awaji Criteria possible/probable ALS patients (17 male; 9 female; mean age 58.6 ± 1.9 years. Results were compared with 21 age matched healthy controls. Results Short interval intracortical inhibition (SICI) was globally reduced ( P P Conclusion There is a global increase in cortical excitability in ALS, further characterised by a preferential increase in cortical excitability of the APB and FDI muscles, which may underlie the clinical development of the ALS split-hand sign.

1. Cortical hyperexcitability of the thenar group of intrinsic hand muscles may contribute to the split-hand sign in ALS

1. Cortical hyperexcitability of the thenar group of intrinsic hand muscles may contribute to the split-hand sign in ALS

Split-hand index for the diagnosis of amyotrophic lateral sclerosis

ObjectivePreferential wasting of the thenar group of muscles, the split hand sign, appears to be a specific feature of ALS. The present study developed a novel split-hand index (SI) and assessed its diagnostic utility in ALS. MethodsOne hundred and seventy consecutive patients with neuromuscular symptoms (44 ALS, 126 patients with other neuromuscular disorders) were prospectively recruited according to standards for reporting of diagnostic accuracy (STARD) criteria. The SI was derived by dividing the product of the compound muscle action potential (CMAP) amplitude recorded over the first dorsal interosseous and abductor pollicis brevis by the CMAP amplitude recorded over the abductor digiti minimi. ResultsThe SI was significantly reduced in ALS patients (ALS 3.5±0.6; patients with other neuromuscular disorders 9.1±0.3, P<0.0001), particularly in limb-onset ALS (2.3±0.5, P<0.0001). Receiver operating characteristic curve analysis indicated that SI reliably differentiated ALS from patients with other neuromuscular disorders (area under curve ALS 0.83, P<0.0001) with an optimal SI cut-off value of 5.2 exhibiting a sensitivity of 74% and specificity 80%. ConclusionsThe split-hand index robustly differentiates ALS from mimic disorders. SignificanceThe split-hand index is a simple measure that could be utilized in a standard neurophysiology setting. A reduction in SI distinguishes ALS from mimic disorders, potentially facilitating an earlier diagnosis of ALS.

The split hand sign

Amyotrophic Lateral sclerosis (ALS) is a disease characterized by pure motor asymmetric wasting of various muscles with associated upper motor neuron signs. The split hand sign, which is because of dissociated muscle weakness in the hands (thenar muscles disproportionately wasted as compared to the hypothenar muscles) is a useful clinical sign for bed side diagnosis of ALS.