Page 37 - Read Online
P. 37

Kim et al.                                                                                                                                                     Common diseases mimicking lumbar disc herniation

                                                              course on the bone, external compression neuropathy
                                                              is not infrequent. However, EN has been reported in
                                                              patients whose daily activities failed to account for its
                                                              elicitation. [48-50]

                                                              The symptoms are pain and paresthesia of  the
                                                              affected area  on the lateral  aspect of the lower  calf
                                                              and the dorsum of  the foot.  Drop foot  is a severe
                                                              symptom, although some patients report only pain and
                                                              paresthesia without severe paresis. [48-52]  Walking  and
                                                              prolonged standing may lead to symptom exacerbation
                                                              and intermittent claudication.
           Figure 6: The common peroneal nerve (arrow) runs around the
           fibular head, then between the soleus and the peroneus longus   Diagnosis and treatment
           muscle (PLM) (*), and then into the PLM. Patients experience pain
           and paresthesia of the affected area, the lateral aspect of the lower   CPN-EN cannot be diagnosed radiologically. While
           calf, and the dorsum of the foot (**)              nerve conduction studies may be useful, the anomaly
                                                              may not be detectable in patients with dynamic
           anterior lateral region of the thigh; they are elicited by   neuropathy-like intermittent claudication. [48-51,53]  In these
           hip joint movement and alleviated by squatting. Some   situations,  it  can  be  difficult  to  distinguish  CPN-EN
           patients complain of intermittent claudication. [38,41,42]  from lumbar spine disease because the symptomatic
                                                              area is similar to L5 radiculopathy with intermittent
           Diagnosis and treatment                            claudication. [48-50]   CPN-EN diagnosis is  based on
           The  symptoms  above and  Tinel-like signs at  the   clinical symptoms. Although the Tinel-like sign is useful
           nerve penetration site inside the superior  iliac spine   diagnostic information, it may be absent. [51]
           are diagnostically  relevant. In some patients without
           clear  Tinel-like symptoms, the disappearance  of   Repetitive plantar flexion of the ankle joint is a useful
           symptoms after nerve block is useful for a diagnosis.   provocation test because the CPN is entrapped by
           Electrophysiological  studies  can also be helpful.   the PLM and soleus muscle; [48,49]  these muscles are
           Patients with symptoms clearly attributable to LFCN-  most heavily loaded during maximum plantar flexion.
           EN may report perception  anomalies  on the outside   CPN-EN results in intermittent claudication.  At a
           of the thigh when the nerve is compressed  in the   cutoff of 110 s, sensitivity and specificity were 94.1%,
           pelvis  or in the presence  of a retroperitoneal  tumor.   suggesting  that  the  repetitive  plantar  flexion  test  is
           Consequently, pelvic lesions must be ruled out when   diagnostically useful. [48]
           blocking fails to be effective.
                                                              When conservative treatment fails, surgical neurolysis
           Conservative therapy and nerve block are effective in   around  the  fibular  head  under  local  anesthesia  is  a
           90% of patients. [42-44]   Tagliafico  et al. [42]  reported that   useful  treatment. It is important  to intraoperatively
           80% of patients improved after a single block; others   confirm sufficient decompression by ankle movement
           required 2 blocks to decrease symptoms. The nerve   because dynamic neuropathy is an important factor in
           block is applied at the site with Tinel-like symptoms,   CP-NEN etiology.
           2 cm inside and 2 cm below the anterior superior iliac
           spine. As  the  anesthetic  infiltrates  the  femoral  nerve   Superficial peroneal nerve EN
           running on the inside, approximately 5% of patients   Definition and symptoms
           experience transient femoral nerve paralysis. [43,45]   CPN-EN  is  more  common  than  superficial  peroneal
           Non-responders  to  conservative  therapy  may  require   nerve  (SPN)-EN.  The SPN bifurcates  from the CPN
           neurolysis or neurectomy under local anesthesia. [38,46,47]
                                                              around the fibular head and runs along the peroneal
           Common peroneal nerve EN                           tunnel between the peroneus longus/brevis  muscles
                                                              and the extensor digitorum longus muscle. The SPN
           Definition and symptoms                            can be entrapped in this area.
           Common peroneal nerve (CPN)-EN is  the  most
           common peripheral entrapment neuropathy eliciting leg   Patients with SPN entrapment report pain  and
           symptoms. The CPN runs around the fibular head and   paresthesia in the affected area, the lateral aspect
           then between the soleus and peroneus longus muscle   of the lower  calf, and the dorsum of the foot. Styf
           (PLM) to the inner  PLM  [Figure 6]; it can become   and Morbergfound  SPN entrapment  in 17 of 480
           entrapped  in this area. As the nerve runs a shallow   (3.5%) patients with chronic leg pain. [54]  According to
                          Mini-invasive Surgery ¦ Volume 1 ¦ June 30, 2017                                 47
   32   33   34   35   36   37   38   39   40   41   42