Incidence and predictive factors of double crush syndrome in patients undergoing cervical surgery: a database study.

BACKGROUND: Double crush syndrome (DCS) is characterized by multiple compression sites along a single peripheral nerve. It commonly presents with persistent distal symptoms despite surgical treatment for cervical radiculopathy. Management typically involves nerve release of the most symptomatic site. However, due to overlapping symptoms with cervical radiculopathy, patients may undergo cervical surgery prior to DCS diagnosis. Due to its rarity and frequent misdiagnosis, the authors aim to utilize a large national database to investigate the incidence and associations of DCS. METHODS: The Pearldiver database was utilized to identify patients undergoing cervical surgery for the management of cervical radiculopathy. Patients were stratified into three cohorts based on their clinical course before and after cervical surgery. The primary outcome was the prevalence of DCS, and secondary outcomes included an evaluation of predictive factors for each Group, using a significance level of P < 0.05. RESULTS: Among 195,271 patients undergoing cervical surgery for cervical radiculomyelopathy, 97.95% were appropriately managed, 1.42% had potentially mids-diagnosed DCS, and 0.63% were treatment-resistant. Diabetes and obesity were significant predictors of potentially misdiagnosed DCS (P < 0.05). CONCLUSION: This study presents data indicating that 1.42% of patients who receive cervical surgery may have underlying DCS and potentially benefit from nerve release prior to undergoing surgery. A concurrent diagnosis of diabetes and obesity may predict an underlying DCS.

Double entrapment neuropathy of the ulnar nerve at the elbow and the wrist : double crush syndrome?

BACKGROUND: Double crush syndrome refers to a nerve in the proximal region being compressed, affecting its proximal segment. Instances of this syndrome involving ulnar and cubital canals during ulnar neuropathy are rare. Diagnosis solely through clinical examination is challenging. Although electromyography (EMG) and nerve conduction studies (NCS) can confirm neuropathy, they do not incorporate inching tests at the wrist, hindering diagnosis confirmation. We recently encountered eight cases of suspected double compression of ulnar nerve, reporting these cases along with a literature review. METHODS: The study included 5 males and 2 females, averaging 45.6 years old. Among them, 4 had trauma history, and preoperative McGowan stages varied. Ulnar neuropathy was confirmed in 7 cases at both cubital and ulnar canal locations. Surgery was performed for 4 cases, while conservative treatment continued for 3 cases. RESULTS: In 4 cases with wrist involvement, 2 showed ulnar nerve compression by a fibrous band, and 1 had nodular hyperplasia. Another case displayed ulnar nerve swelling with muscle covering. Among the 4 surgery cases, 2 improved from preoperative McGowan stage IIB to postoperative stage 0, with significant improvement in subjective satisfaction. The remaining 2 cases improved from stage IIB to IIA, respectively, with moderate improvement in subjective satisfaction. In the 3 cases receiving conservative treatment, satisfaction was significant in 1 case and moderate in 2 cases. Overall, there was improvement in hand function across all 7 cases. CONCLUSION: Typical outpatient examinations make it difficult to clearly differentiate the two sites, and EMG tests may not confirm diagnosis. Therefore, if a surgeon lacks suspicion of this condition, diagnosis becomes even more challenging. In cases with less than expected postoperative improvement in clinical symptoms of cubital tunnel syndrome, consideration of double crush syndrome is warranted. Additional tests and detailed EMG tests, including inching tests at the wrist, may be necessary. We aim to raise awareness double crush syndrome with ulnar nerve, reporting a total of 7 cases to support this concept.

Patients With and Without Double Crush Syndrome Achieve Similar Rates of Clinical Improvement Following Carpal Tunnel Release.

BACKGROUND: The purpose of this study is to compare outcomes of carpal tunnel release (CTR) in patients with and without double crush syndrome (DCS), defined as concurrent carpal tunnel syndrome (CTS) and cervical radiculopathy at C5-T1 on preoperative nerve conduction studies. METHODS: Patients with preoperative nerve conduction studies who underwent unilateral, isolated CTR were retrospectively identified. All patients completed preoperative and 3-month postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) upper extremity (UE) and pain interference (PI), and Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaires, and responded to the anchor question: "Since your treatment, how would you rate your overall function?" (much worse, worse, slightly worse, no change, slightly improved, improved, much improved). Preoperative, postoperative, and changes in scores for UE, PI, and QuickDASH were compared, as were the anchor question responses and rates of achieving the minimal clinically important difference (MCID). RESULTS: Sixty-three patients with DCS and 115 patients with CTS only were included. At 3- to 4-month follow-up, absolute and change in UE, PI, and QuickDASH scores were not statistically different between patients with DCS and CTS. Rates of anchor question response and MCID achievement were comparable for patients with CTS only and DCS on each questionnaire. The MCID achievement ranged from 48.4% to 68.8% in the unmatched cohort and 48.4% to 60% in the matched group. CONCLUSIONS: At 3 to 4 months, patients with DCS experience similar patient-reported symptomatic and functional improvement, and achieve MCID of outcome measures at comparable rates to patients with CTS only. For patients with nerve compression at the carpal tunnel and cervical spine, CTR is a reasonable first step prior to proceeding with cervical spine decompression.

Subacute Ulnar Nerve Compression Neuropathy Following Hand Crush Injury in the Setting of Intracanal Accessory Abductor Digiti Minimi: A Double Crush Phenomenon.

Anatomical variations within Guyon's canal such as an accessory abductor digiti minimi are described as causes of ulnar nerve compression. Here we present a unique case of delayed ulnar neuropathy following treatment of left fourth metacarpal base fracture with percutaneous pinning fixation and an uncomplicated two month postoperative course. He returned with new ulnar sensory loss and motor weakness. EMG demonstrated nerve compression with CT identifying an accessory abductor digiti minimi in Guyon's canal. Following Guyon's canal release with partial accessory muscle resection, there was immediate sensory and progressive motor recovery with resolution of clawing. Delayed compression by an accessory abductor digiti minimi following trauma has not been described, suggestive of double-crush phenomenon. The accessory muscle was an asymptomatic variable (first "crush") and with the second "crush" of post-surgical changes resulting in pathological nerve compression. With delayed onset ulnar neuropathy after trauma, surgeons should consider possible accessory structures.

Double Crush Syndrome of the Median Nerve: A Literature Review

Double crush syndrome (DCS) is defined as the compressive involvement of the same peripheral nerve in different segments.When this syndrome affects the median nerve, a proximal compression of a spinal nerve that will constitute this structure (often the spinal nerve at the C6 vertebra) is usually noted at the cervical spine level as a herniated disc and as a distal compression at the level of the carpal tunnel. Epidemiological data on median nerve compromise by DCS are still very scarce in the medical literature. The diagnosis can be inferred by symptoms and signs occurring proximally and distally in the arm, as well as by alterations revealed by upper limb electromyography and neuroimaging studies, such as magnetic resonance imaging (MRI) of the cervical spine. Nowadays, information on which compressed neuroanatomical point should be initially addressed still depends on further studies. Limited data infer that these patients, when submitted to surgical treatment in only one of the median nerve compression points, evolve with worse functional outcomes than the surgically-treated group with carpal tunnel syndrome without DCS.