Natural history and neuro-oncological approach in spinal gangliogliomas: a systematic review

To describe the natural history of spinal gangliogliomas (GG) in order to determine the most appropriate neuro-oncological management. A Medline search for relevant publications up to July 2023 using the key phrase "ganglioglioma spinal" and "ganglioglioma posterior fossa" led to the retrieval of 178 studies. This corpus provided the basis for the present review. As an initial selection step, the following inclusion criteria were adopted: (i) series and case reports on spinal GG; (ii) clinical outcomes were reported specifically for GG; (iii) GG was the only pathological diagnosis for the evaluation of the tumor; (iv) papers written only in English was evaluated; and (v) papers describing each case in the series were included. The World Health Organization (WHO) 2021 grading criteria for gangliogliomas were applied. A total of 107 tumors were evaluated (63 from male patients and 44 from female patients; 1.43 male/1.0 female ratio, mean age 18.34 ± 15.84 years). The most common site was the cervical spine, accounting for 43 cases (40.18%); GTR was performed in 35 cases (32.71%) and STR in 71 cases (66.35%), while this information was not reported in 1 case (0.94%). 8 deaths were reported (7.47%) involving 2 males (25%) and 6 females (75%) aged 4-78 years (mean 34.27 ± 18.22) years. GGs located on the spine displayed the same gender ratio as these tumors in general. The most frequent symptom was pain and motor impairment, while the most prevalent location was the cervical spinal cord. GTR of the tumor posed a challenge for neurosurgeons, due to the difficulty of resecting the lesion without damaging the spinal eloquent area, explaining the lower rate of cure for this tumor type.

Bilateral ictal EEG is associated with better memory outcome after hippocampal sclerosis surgery

OBJECTIVE

To compare memory outcomes after surgery for unilateral hippocampal sclerosis (HS)-associated epilepsy in patients with unilateral and bilateral ictal electrographic involvement.

METHODS

We prospectively evaluated HS patients, aged 18-55 years and IQ ≥70. Left (L) and right (R) surgical groups underwent noninvasive video-EEG monitoring and Wada test. We classified patients as Ipsilateral if ictal EEG was restricted to the HS side, or Bilateral, if at least one seizure onset occurred contralaterally to the HS, or if ictal discharge evolved to the opposite temporal region. Patients who declined surgery served as controls. Memory was evaluated on two occasions with Rey Auditory-Verbal Learning Test and Rey Visual-Design Learning Test. Baseline neuropsychological test scores were compared between groups. Pre- and postoperative scores were compared within each group. Reliable change index Z-scores (RCI) were obtained using controls as references, and compared between surgical groups.

RESULTS

We evaluated 64 patients. Patients were classified as: L-Ipsilateral (9), L-Bilateral (15), L-Control (9), R-Ipsilateral (10), R-Bilateral (9), and R-Control (12). On preoperative evaluation, memory performance did not differ among surgical groups. Right HS patients did not present postoperative memory decline. L-Ipsilateral group presented postoperative decline on immediate (P = 0.036) and delayed verbal recall (P = 0.011), while L-Bilateral did not decline. L-Ipsilateral had lower RCI Z-scores, indicating delayed verbal memory decline compared to L-Bilateral (P = 0.012).

SIGNIFICANCE

Dominant HS patients with bilateral ictal involvement presented less pronounced postoperative verbal memory decline compared to patients with exclusive ipsilateral ictal activity. Surgery was indicated in these patients regardless of memory impairment on neuropsychological testing, since resection of the left sclerotic hippocampus could result in cessation of contralateral epileptiform activity, and, therefore, improved memory function.