Over the years, there have been many discussions on the selection indication for surgical approaches to cervical spine diseases including OPLL, especially cervical spine degenerative diseases. The idea of approaching the lesion anteriorly with the main seat in the ventral side of the cervical spine is a perfect logical strategy and vice versa. However anterior intervertebral bony fusion is essential, except for some surgical techniques, after correct decompression of the spinal cord/nerve root from the ventral side. There is also the issue of adjacent intervertebral disorders after spinal fusion occurring, and it is more important to carefully observe long-term follow-up in Japan, where the frequency of developmental spinal canal stenosis is higher than overseas. As a surgical indication for the anterior or posterior approach of current textbook-like cervical spine degenerative disease : 1) anterior approach if the lesion is within 2 vertebrae, posterior approach if more. 2) In the past, those with kyphosis were contraindications for posterior decompression, but the posterior decompression effect of the spinal cord is expected if the cervical spine arrangement has a local kyphosis of 13 degrees or less is present. 3) For non-elderly patients with a background of developmental spinal canal stenosis, there is another strategy to choose the posterior approach first due to adjacent intervertebral disorders. 4) The OPLLs with a K-Line (+) is indicates a posterior approach, on the other hand, ones with a K-Line (−) indicate an anterior approach.
Although each approach is a safe and established procedure, it is important to understand the type and frequency of complications and tips to prevent them. Regarding selecting the best surgical approach for cervical disorders, it is not a uniform one, but it must be generally selected considering age, general condition, and the social and family background of each patient all together. In addition, the use of artificial intervertebral discs will begin soon in Japan. It seems that improvements will also be made in anterior/posterior surgical selection for cervical degenerative disorders.
There is no clear consensus on spinal fusion criteria for lumbar degenerative disease based on high quality evidence. The significances of the addition of fusion surgery to posterior decompression in surgical interventions for these diseases is the mechanical removal of a painful unstable interbody segment, assumed to be the cause of appearance and/or an exacerbating factor of low back pain and neurological symptoms, in addition to correction of the spinal deformity. In this article, we describe several unresolved issues, namely, pathological differentiation of low back pain, fusion surgery for discogenic low back pain, radiological definition of spinal instability, and the clinical impact of vertebral slippage and/or instability, which are considered grounds for selecting fusion surgery but remain controversial. Following the more recently the development and spread of minimally invasive posterior decompression techniques, it is now necessary to reevaluate the fusion criteria for degenerative spondylolisthesis as indicated in recent years by the dramatic increase in fusion surgery. We therefore discuss the indications for and problems of posterior decompression alone and fusion surgery for degenerative lumbar disease, focusing on degenerative spondylolisthesis, and furthermore give an overview of a lateral lumbar interbody fusion.
The majority of patients with osteoporotic vertebral fracture (OVF) recover from their symptoms without surgery. But some OVF cases have the risk of delayed neurological deficits caused by neural compression from a proceeding deformity of the vertebral body. And once the patients have OVF, it is well known that their risks for another osteoporotic fracture increase. This downward spiral ultimately results in the loss of healthy life and an increase in mortality. In today’s “super-aged society” our neurosurgeons also encounter OVF patients not only in surgical situations but also at outpatient clinics. So we have to be aware of the clinical options for treating osteoporosis.
Many patients come to the hospital with complaints of numbness and pain in their upper and lower limbs. In this situation, the most important thing in conducting a differential diagnosis is to ensure that the proper neurological examinations are conducted. The brain, spinal cord, nerve roots and peripheral nerves are the responsible sites for neurological symptoms. After making a conceivable diagnosis by consolidating the patients symptoms and neurological examination results, we perform imaging and electrophysiological studies and finally determine the affected site. Some of the more common peripheral nerve entrapment neuropathies are carpal tunnel syndrome, cubital tunnel syndrome, thoracic outlet syndrome, peroneal nerve entrapment neuropathy, tarsal tunnel syndrome and so on. In peripheral nerve entrapment disorders, comprehending the skin innervation area of numbness or pain is a key point in making an accurate diagnosis. Tinel’s sign and symptom induction tests according to patient some posture are still very useful in the diagnosis of peripheral nerve disorders. Recently, imaging studies such as MRI and high-resolution ultrasonography have been developed and have become more reliable for diagnosing of the severity of the nerve degeneration, but electrophysiological examination is still important. For peripheral nerve entrapment disorders, immobilization or rest of the affected site is very useful in the early stage, and conservative treatment such as physical therapy and medication therapy should also be performed. Surgical treatment might be recommended for the cases with severe symptoms, symptom progression and daily life impairment by severe pain.
Japan is different from other countries in the point of clinical practice. Neurosurgeons must diagnose the disease, perform surgeries and then take care of patients. As the diagnosis, surgery and postoperative follow-up are not independent for Japanese neurosurgeons, so patient feedback can be reliably obtained, which may contribute to improving the diagnostic ability and surgical techniques. Although neurologists are also involved in diagnosis and orthopedic surgeons are also involved in the surgical treatment, surgical treatment for peripheral nerve entrapment disorders should be guided in the future by neurosurgeons who can handle the whole nervous system.
Although worldwide, peripheral nerve entrapment neuropathy is not uncommon, it is rarely encountered by Japanese neurosurgeons. Carpal tunnel syndrome and ulnar neuropathy at the elbow are treated at relatively many Japanese neurosurgical institutions ; their incidence is lower than of superior cluneal nerve neuropathy, common peroneal nerve neuropathy, and tarsal tunnel syndrome.
We describe our surgical approach to treat carpal tunnel syndrome, ulnar neuropathy, superior cluneal nerve neuropathy, common peroneal nerve neuropathy, and tarsal tunnel syndrome.
Since surgery for these typical peripheral entrapment neuropathies can be performed less invasively under local anesthesia, it can be used to treat elderly patients. It requires sufficient decompression under a microscope using microsurgical techniques. If dynamic neuropathy is involved, dynamic factors must be considered. After this type of surgery, neither external fixation nor restriction of the activities of daily living is needed. We obtained drastic symptom improvement that satisfied both patients and surgeons.
We suggest that our method of addressing typical peripheral entrapment neuropathies be added to existing neurosurgical treatments.
Dysembryoplastic neuroepithelial tumor (DNT) is a type of brain tumor that causes refractory epilepsy. We present the case of a 13-year-old boy with temporal lobe epilepsy. Magnetic resonance imaging (MRI) revealed multiple lesions in the right temporal lobe, basal ganglia, deep white matter, and lateral ventricle. Serial MRI showed morphological changes of contrast-enhanced lesions, but fluorodeoxyglucose-positron emission tomography (FDG-PET) revealed hypometabolic lesions. Subtraction ictal single-photon emission computed tomography coregistered to MRI (SISCOM) and ictal electroencephalography (EEG) suggested the seizure onset zone might be located in the right temporal lobe. We performed right temporal lobectomy, and pathological diagnosis confirmed DNT. At one year post-surgery, the patient has achieved seizure-free status, and the remaining lesions have not increased. Multifocal DNT is extremely rare, and treatment strategy was difficult to determine in this case. Surgery should be performed when appropriate after clarifying the treatment purpose.
Pilocytic astrocytoma (PA) is a benign glioma that usually occurs in children and adolescents. We present with a very rare case of PA that arose from the cervicomedullary junction in an adult, whose onset was obstructive hydrocephalus caused by intratumoral hemorrhage. A 51-year-old man presented with headache, blurred vision, and difficulty in gait over a week. Computed tomography revealed a high-density mass at the dorsal medulla, associated with ventricular dilatation. Magnetic resonance imaging (MRI) revealed a heterogeneously enhanced mass lesion at the dorsal cervicomedullary junction, with significant brain stem compression.
Intratumoral hemorrhage was also recognized by T2* image. The sharply demarcated appearance on MRI resembled an extra axial tumor such as foramen magnum neurinoma. The patient underwent surgical extirpation of the tumor via a midline suboccipital approach with C1 laminectomy. The tumor was subtotally removed and the postoperative course was uneventful with resolution of the hydrocephalus. The histopathological study demonstrates typical findings of PA with a mixture of recent and previous hemorrhage. Periodic MRIs reveal no local recurrence, and no leptomeningeal dissemination, during the 2-year follow-up period. Finally, the clinical, neuroradiological, and pathophysiological characteristics of this rare case are discussed.