Hormonal modulation after deep brain stimulation and spinal cord stimulation: a scoping review mapping evidence...

Deep brain stimulation (DBS) and spinal cord stimulation (SCS) are widely used neuromodulation therapies for movement disorders, pain, neuropsychiatric conditions, and other indications. Beyond symptom control, both techniques may modulate neuroendocrine and metabolic pathways, but the available evidence is fragmented across targets, indications, and hormone systems. This review aims to map the existing human and preclinical evidence on hormonal and neuroendocrine changes associated with DBS and SCS across different stimulation targets and clinical indications.

We conducted a scoping review following PRISMA guidelines. Experimental and clinical studies, case series, and case reports reporting hormonal, endocrine, or neuropeptide outcomes during or after DBS or SCS were eligible. Data were charted for study design, population (human/animal), indication, stimulation target/level, stimulation type, hormones assessed, direction of hormonal change, associations with clinical outcomes, and side effects. Given heterogeneity of designs and outcomes, results were synthesized narratively and organized by stimulation modality.

Eighteen studies were included: thirteen focused on DBS and five on SCS. DBS of the subthalamic nucleus, hypothalamus, nucleus accumbens, bed nucleus of the stria terminalis, medial forebrain bundle, and basolateral amygdala was associated with changes in prolactin, TSH, ACTH, cortisol/corticosterone, testosterone, thyroid hormones, ghrelin, NPY, insulin, leptin, and oxytocin, with some studies linking these changes to weight gain, mood elevation, pain behavior, or OCD symptom trajectories. SCS studies reported modulation of leptin and catecholamines in humans, oxytocin release in analgesia models, and norepinephrine dynamics in cardiac and autonomic contexts.

DBS and SCS can modulate multiple endocrine axes in a target- and indication-specific manner, but the literature is sparse, heterogeneous, and largely exploratory, especially for SCS. Systematic hormone monitoring in neuromodulation trials, with standardized reporting of endocrine outcomes, is needed to clarify mechanisms, predict responders, and anticipate metabolic and neuropsychiatric side effects.