Severe Amnesic Syndrome and Collecting Behavior After Surgery for Craniopharyngioma

Acute amnestic syndrome in fornix lesions: a systematic review of reported cases with a focus on differential diagnosis

Introduction

Acute amnestic syndrome is an uncommon clinical presentation of neurological disease. Differential diagnosis encompasses several syndromes including Wernicke-Korsakoff and transient global amnesia (TGA). Structural lesions of the fornix account for a minority of cases of acute amnestic syndromes. Etiology varies from iatrogenic injury to ischemic, inflammatory, or neoplastic lesions. A prompt diagnosis of the underlying pathology is essential but challenging. The aim of this review is to systematically review the existing literature regarding cases of acute amnestic syndrome associated with non-iatrogenic lesions of the fornix.

Methods

We performed a systematic literature search on PubMed, Scopus, and Web of Science up to September 2023 to identify case reports and case series of patients with amnestic syndrome due to fornix lesions. The systematic review was conducted according to PRISMA guidelines. The research was limited to articles written in English. Cases of fornix damage directly ascribable to a surgical procedure were excluded.

Results

A total of 52 publications reporting 55 cases were included in the review. Focusing on acute/subacute onset, vascular etiology was highly prevalent, being responsible for 78% of cases, 40/55 (74%) of which were due to acute ischemic stroke. The amnestic syndrome was characterized by anterograde amnesia in all patients, associated with retrograde amnesia in 27% of cases. Amnesia was an isolated presentation in most cases. Up to two thirds of patients had persistent memory deficits of any severity at follow-up.

Discussion

Acute amnestic syndrome can be rarely caused by fornix lesions. In most cases of acute/subacute presentation, the etiology is ischemic stroke, mainly caused by strokes involving the subcallosal artery territory. The differential diagnosis is challenging and a distinction from common mimics is often difficult on a clinical basis. A high index of suspicion should be maintained to avoid misdiagnosis and provide adequate acute treatment to patients with time-dependent disease, also employing advanced neuroimaging. More research is needed to better understand the outcome and identify prognostic factors in patients with amnestic syndrome due to fornix lesions.

Could deep brain stimulation be a possible solution for acquired hypothalamic obesity?

Objective

Hypothalamic dysfunction may result in morbid obesity as a consequence of decreased energy expenditure, decreased feelings of satiety, and increased fat storage. In patients with hypothalamic dysfunction, neurobehavioral dysfunction is also often present. Currently, no effective treatment has been found for hypothalamic obesity (HO). We hypothesize that deep brain stimulation (DBS) may be an effective treatment for patients with hypothalamic dysfunction, aiming to treat HO as well as the neurobehavioral dysfunction.

Methods

A systematic search was conducted in the PubMed, EMBASE and Cochrane Library databases for studies published until May 2022 reporting on DBS for the treatment of HO.

Results

Three studies met the predetermined inclusion criteria, with in total six patients treated with DBS for HO, of which five patients with Prader-Willi syndrome (PWS) and one patient with HO after treatment for craniopharyngioma (CP). Targets of DBS included the lateral hypothalamic area (LHA) and the nucleus accumbens (NAcc). In patients with PWS, LHA-DBS was associated with a mean increase of Body Mass Index (BMI) (+5.8%), with no change in hormonal levels, results of blood workup, sleep, or neuropsychological evaluation. In the patient with CP, NAcc-DBS was associated with a decrease in BMI (-8.7%) and a subjective increase in mental health, energy and willingness to act, and no feeling of increased appetite. No objective measurements on neurobehavioral function were reported. No severe adverse events were reported in these cases. Mild to moderate adverse events included hypomanic symptoms and infection. All patients with a described follow-up period (n = 5) were able to sustain the treatment for at least 6 months with few interruptions.

Conclusion

There is limited research reporting on DBS for HO. The effectiveness differed across studies and the evidence is limited. Although there may be potential for DBS treatment in the severe-refractory condition of HO in patients with CP, more research is needed for target selection and evaluation of effectiveness.

Memory Disorders in Children With Central Nervous System Germ Cell Tumors

Memory disorders in children and adolescents with brain tumors are rare, but devastating to social, academic, and vocational development. Many pediatric patients with intracranial germ cell tumors (GCTs) complain of memory difficulties. This study investigated memory across a series of GCT patients. A total of 33 GCT patients were retrospectively examined for diagnosis, imaging results, intelligence quotient, treatment variables, evidence of increased intracranial pressure at diagnosis, and memory. The incidence of amnesia in GCT patients was 55%. Memory disturbance could not be predicted by intelligence quotient, treatment, location of lesion, or hydrocephalus at diagnosis. The high incidence of memory deficits in GCT patients suggests a risk to memory in patients with GCT. Formal memory assessment should be considered in all patients with central nervous system GCTs. Specific counseling and planning to assist in adjustment and to ensure safety should be considered standard care for those with memory deficits. The nurse should be instrumental in facilitating understanding of this specific injury in the brain tumor population.

Memory deficits in patients with pediatric CNS germ cell tumors

BACKGROUND

Germ cell tumors (GCT) of the central nervous system including germinomas and nongerminomatous germ cell tumors are rare neoplasms most commonly affecting children and adolescents. Many GCT patients seen at The Children's Hospital Denver complain of memory difficulties at the time of presentation, or demonstrate memory difficulties when assessed. Although case studies suggest that memory deficits may be associated with GCT, this is the first study to investigate memory function across a series of pediatric intracranial GCT patients.

PROCEDURE

A total of 26 GCT patients were retrospectively examined for diagnosis, imaging results, intelligence quotient, treatment variables, evidence of increased intracranial pressure at diagnosis, and memory function. Patient Full Scale IQ was measured using the Wechsler intelligence scales. Memory was evaluated with the California Verbal Learning Test.

RESULTS

The incidence of amnesia in GCT patients was 42%. GCT patients with amnesia were significantly older at diagnosis than those who did not develop amnesia. There was no association between hydrocephalus at presentation or having received radiation and the presence of memory deficits. Several cases of amnesia were not associated with involvement of classic memory structures.

CONCLUSION

The high incidence of measurable memory deficits in GCT patients suggests that amnesia may be a significant risk in this patient population. Memory assessment at diagnosis and appropriate follow-up services may prove beneficial for GCT patients.