Motor Conduction Studies and Handgrip in Hereditary TTR Amyloidosis: Simple Tools to Evaluate the Upper Limbs

Abstract

PurposeHereditary transthyretin amyloidosis with polyneuropathy (ATTRv) is caused by mutations in the TTR gene, leading to misfolded monomers that aggregate generating amyloid fibrils. The clinical phenotype is heterogeneous, and characterized by a multisystemic disease affecting the sensorimotor and autonomic functions along with other organs.Materials and MethodsAll the patients were assessed by complete neurological assessment, neurophysiological evaluation, of the median nerve, and handgrip analysis. The data are presented as means and standard deviations. Parametric and non-parametric assessments have been performed to identify differences between groups. Pearson's correlation has been carried out when appropriate.ResultsTwenty patients with ATTRv (66.1 ± 8.4 years; eight females) and 30 controls (61.1 ± 11.6 years; 16 females) were enrolled. Handgrip strength was reduced in patients with ATTR in both right and left hands compared to the controls. Significant differences were found between patients and controls in the right (handgrip right, HGSR TTR 21.1 ± 13 kg vs. HGSR Control 29.4 ± 11.3 kg, p = 0.017) and left (handgrip left, HGSL TTR 22.2 ± 10.7 kg. vs. HGSL Control 31 ± 11.3 kg, p = 0.007). NIS and CMAP amplitude of the median nerve were related to HGS measures for both hands in patients with ATTRv.ConclusionsThe progression of bilateral carpal tunnel syndrome is related to neurophysiological data in the median nerve in ATTRv. Also, handgrip measures might represent an important tool for the assessment of disease progression in ATTRv. We propose using a combination of CMAP amplitude and HGS for the assessment of hand motor strength in ATTRv.

Patisiran Enhances Muscle Mass after Nine Months of Treatment in ATTRv Amyloidosis: A Study with Bioelectrical Impedance Analysis and Handgrip Strength

“…Moreover, Anbarasan et al demonstrated how it represents a functional outcome measure that significantly improved after mini carpal tunnel release [20]. A previous study from our group proved that HGS is reduced in ATTRv patients, probably because of bilateral carpal tunnel syndrome and polyneuropathy [16]. Furthermore, HGS showed a negative correlation with NIS scores, while it was positively correlated with the neurophysiological evaluation of the median compound motor action potential amplitude [16].…”

“…Some researchers are involved in the evaluation of serum biomarkers of neuropathy such as light chain neurofilaments [15]. Of interest, muscle strength can be measured through handgrip tools [16]. The handgrip strength (HGS) test evaluates the force that a person is able to produce when grasping an object.…”

Electrodiagnostic profile of conduction slowing in amyotrophic lateral sclerosis

“…Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv) can mimic ALS, particularly in the predominantly or purely motor neuropathy as well as in the case of thenar muscles weakness and hypotrophy related to CTS which is frequently observed in early stage ATTRv [ 14 , 22 , 23 ]. A recent study investigated motor conduction studies and handgrip in 20 patients with ATTRv.…”

“…A recent study investigated motor conduction studies and handgrip in 20 patients with ATTRv. It demonstrated a significant prolongation of DML, reduction of MCV and handgrip strength in the ATTRv group compared to the control group [ 23 ]. In our study, although conduction slowing occurred in our ALS patients, it was associated with clinical and neurophysiological findings fulfilling the Escorial revised criteria of the World Federation of Neurology for ALS and making a misdiagnosed ATTRv very unlikely.…”

Carpal Tunnel Syndrome: Neuropathic Pain Associated or Not with a Nociplastic Condition

“…The final step involves screening for sensitivity to other stimuli, including sensitivity to other stimuli, such as sound, light, or odors, and the presence of underlying comorbid medical conditions or other central nervous system-associated symptoms, e.g., poor sleep quality, fatigue and cognitive problems [ 12 ]. For instance, different underlying medical conditions, such as diabetes [ 61 ], rheumatoid arthritis [ 62 ] or hereditary transthyretin amyloidosis with polyneuropathy [ 63 ], are considered to be potential risk factors of CTS. In addition, as it was previously commented, the presence of psychological disturbances, e.g., depression, and poor sleep is present in almost 40% of subjects with CTS [ 44 , 45 , 46 ].…”