. 2023 Oct 13;66(1):1–30. doi: 10.1007/s00234-023-03226-6

Table 2.

Symptoms associated with Tarlov cysts

Author, year, country	Referral cohort, investigations	Tarlov cyst details	Presenting symptoms
Langdown [37] 2005 Australia	• 54-patient cohort (38 women, 16 men) mean age 54.4 years (range 27–83 years) with symptom duration months to years • Referred over a 5-year span for a spinal surgeon specialist opinion for low back pain, sciatica or spinal stenosis	• All cysts occurred in the sacral region • Cysts were frequently multiple in various locations, unilateral, central or bilateral	• Low back pain (n = 30), nerve root pain (n = 17), leg pain (n = 9), and neurological loss (n = 5)
Marino [73] 2013 Italy	• 157-patient cohort (138 women, 19 men) mean age 48 ± 11 years with a mean age at symptom onset at 42 years of age • Between October 2008 and May 2012 referred to a neurosurgical outpatient clinic • Underwent neurological investigations (complete electroneurography of lower limbs), bowel/bladder and gynecological exams • Pain scored by VAS and depression by the Hamilton Depression Rating Scale	• Cases involved single or bilateral sacral cysts • Lumbar cysts (n = 3)	• Almost all with perineal or lower back pain • MRI evidence lumbar and/or sacral disc herniation (95%) • Sphincter disorders (34.4%) similar for women and men) • Sexual dysfunctions higher for men vs women (36.8% vs 28.2%) • Electroneurographic findings (n = 32) were normal • Pain mean VAS score 4.7 ± 2.0 and depression rating scale 18.1 ± 10.4 in the mild severity range (similar for men and women) • Social psychological effects included mood disorders, social, employment issues and loss of jobs
Murphy [74] 2016 Canada	• 213-patient cohort, 289 cysts • Between 2003 and 2012 referred to an interventional neuroradiologist and spine neurosurgeon • Underwent lumbar and dedicated sacral MRI, physical exam, neurological assessment and/or gynecologist or urologist evaluation if pelvic, abdominal or genital symptoms were present • Pain and function assessed by Lumbar Spine Outcomes Questionnaire	• Cysts involved single nerve roots unilaterally (n = 113), single roots bilaterally (n = 78) and more than two roots bilaterally (n = 22) • Location mainly S2 (n = 142) and S3 (n = 120) sacral levels • Cyst size ranged between 2 and 4 cm (n = 143), 8 cysts were greater than 4 cm	• Generalized sacral and/or lumbar pain (89%) • Pelvic pain and/or perineal pain (98%) • Bladder (43%), bowel (29%) • Sexual dysfunctions (43%) • Common neurologic abnormalities included absent Achilles reflex (61%), plantar flexion weakness (41%), reduced rectal sphincter tone (29%), bladder sphincter impairment (43%), cyst-related sensory loss at S1 (8%), S2 (64%), S3, S4, S5 (46%)
Baker [71] 2018 United States	• 65-women cohort, mean age 53 ± 12 years, 89% White • Between July 2004 and October 2015 referred to urogynecology or neurosurgery clinics • Indication for clinic visit, back pain, radicular pain, pelvic pain, sexual dysfunction urinary or bowel dysfunction • Medical and surgical history, physical exam detection of lower extremity numbness or weakness and urodynamic testing	• Sacral cysts mainly located at the S2 or S2/S3 sacral regions • Cyst mean size 17 mm (range 5– 59 mm) • Sacral cysts larger than 10 mm (90%)	• Symptoms by region: lumbosacral (95%), urinary (78%), bowel (55%), central nervous system (40%) and sexual dysfunction (25%) • Commonly reported low back pain (83%), lower extremity pain (75%), positional pain arising to sitting or standing (62%), urinary urgency (54%) and urinary frequency ((48%) • Urodynamic testing (n = 40) with 78% having abnormalities with early bladder filling sensation the most frequent finding • Urinary urge incontinence (31%) vs 7% general population
Hulens [72] 2018 United States	• 33-patient cohort (30 women, 3 men) mean age 49.8 years • Study data collected July 2015 and October 2016 • Comparator group, 42 age-sex matched patients (38 women, 4 men) experiencing long-term back pain or sciatica due to degenerative disorders or inflammatory disease • Nerve conduction tests and electromyography for lumbar and sacral nerve root myotomes • Symptom profiles based on modified International Tarlov Cyst Questionnaire (Feigenbaum 2022)	• Study restricted to Tarlov cysts ≥ 15 mm in diameter	• Symptomatic for mean 9.5 years and were significantly more common in patients with Tarlov cysts vs those with only back pain • Lower limbs [foot pain (24% vs 10%), leg pain (25% vs 5%), foot paresthesia (31% vs 5%), and subjective leg weakness (72% vs 28%)] • Pelvic symptoms [perineal paresthesia (24% vs 5%) dyspareunia (32% vs 5%), and coccygodynia (49% vs 17%)] • Bowel and sphincter [constipation (63% vs 33%), anal pain (57% vs 10%), mild fecal incontinence (55% vs 7%)] • Bladder and urinary sphincter: hesitation (38% vs 5%), retention (55% vs 17%), and frequency (69% vs 38%) • Pain aggravating features sitting (100% vs 74%) or long walks (75% vs 34%) • Reduced social functioning (78% vs 18%), forced to stop working (54% vs 18%)
Lim [42] 2020 United States	• 39-patient cohort (34 women, 5 men) mean age 51.3 years (range 24–83 years) • Between January 2010 and November 2012 referred to an academic chronic pain center having MRI-identified Tarlov cysts and pudendal neuralgia (validated by Nantes criteria), a chronic pelvic pain syndrome	• Cysts mainly located at S2–S3 sacral level (64%) • One cyst outside the pudendal nerve distribution (L5-S1) • Cyst sizes 44% small (< 1 cm), 50% moderate (1–2 cm)	• Pain locations for women in the perineum (n = 7), rectum (n = 14), and vagina (n = 19) and for men in the perineum (n = 4) penis (glans) (n = 2) and scrotum (n = 3) • Comorbid conditions for women including interstitial cystitis (n = 4), pelvic floor tension myalgia (n = 17) and pelvic organ prolapse (n = 7), persistent genial arousal disorder (PGAD) (n = 2) • Pelvic floor tension myalgia in men (n = 2)
Cattaneo [83] 2001 Italy	• 11-patient cohort referred to an outpatient EMG laboratory with lumbosacral MRI documented sacral Tarlov cysts • Sural nerve investigated electrophysiologically	• In 5 patients with sural nerve abnormalities, cysts size ranged from 2 to 3 cm, were located bilaterally (n = 3), or unilateral right (n = 2) and at the S1 to S3 sacral levels	• Symptoms included sciatica (n = 3), bilateral foot paresthesia and pain (n = 1) and 1 was asymptomatic • Sural sensory abnormalities found in five patients (2 women, 3 men) aged 40 to 66 years • Abnormalities were localized to the side of the Tarlov cysts and the size of the cyst was not related to the presence and extent of the nerve damage • Motor nerve conduction was spared demonstrated with normal findings in all subjects accounted for by the location of the cysts at the dorsal root
Hulens [84] 2016 Belgium	• 3 case reports (3 women) • Sural nerve conduction studies and electromyelographic tests evaluating nerve injury and relating to patients’ symptoms	• Multiple Tarlov cysts ranging in size from 6 to 36 mm	• Symptoms included radicular back leg pain, urinary/fecal sphincter disturbances, perineal pain, dyspareunia, and headaches • EMG findings varied in patients with delayed sural nerve response and ano-anal reflex occurring
Hulens [85] 2017 Belgium	• 30-patient cohort (27 women, 3 men) with Tarlov cysts mean age 46 years (range 25–74 years) • Referred to a physical medicine outpatient clinic for unexplained refractory low back, pelvic, perineal and/or leg pain, symptomatic for mean 11.6 ± 12.0 years (range 8 months and 50 years) • Needle EMG studies to evaluate lumbosacral dermatomes	• Cysts located on L5 to S4 nerve roots were commonly bilateral with a mean size of 7.1 mm (range 3 to 36 mm) • Nerve root dilations or smaller Tarlov cysts (< 10 mm) were found in the cervical (C7) to thoracic (TH4) regions for most (23/30) patients	• Symptoms included pain in lower back/sacral pain (83.3%), buttock (80%), coccygeal 47%, perineal 33%, dyspareunia/genital pain (69%); parasthesis in perineum (47%), buttocks (47%), legs (63%), foot/feet (80%) – foot drop (3.3%); bladder dysfunction (77%), bowel dysfunction (70%) • Increased pain with sitting (96.7%) or standing (86.7%) • Sural nerve conduction abnormalities (16.7%) with 4 of the 5 dermatomal abnormalities corresponded to dermatomal pain and/or paresthesia • S1 Hoffman-reflex latency abnormality (23.3%) with 7/7 corresponding to dermatomal pain and/or paresthesia • Ano-anal reflex abnormality (89.3%) with 23/25 corresponding to dermatomal pain and/or paresthesia • Needle EMG abnormalities were found at all levels: L4 (36.7%), L5 (76.7%), S1 (40%), S2 (96.6%), and S3–S4 (75%), with abnormalities corresponding to Tarlov cysts on that nerve root: L4 (7/18), L5 (33/49), S1 (25/58), S2 (32/56), and S3-S4 (37/59)
Hulens [86] 2022 Belgium	• 31 patients (26 women, 5 men) mean age 47 ± 10 years (range 31–74 years) with symptomatic Tarlov cysts larger than 8 mm • Lumbar and sacral nerve root abnormalities investigated for large- and small-fiber neuropathy • Investigations included EDX tests (n = 24) included nerve conduction and needle EMG, and lower leg skin biopsies to assess IENFD (n = 17), 11 patients underwent both IENFD and EDX	• Cysts located mainly in the sacral areas varied in mean size: L4 (n = 3), 8.7 ± 1.2 mm (range 8–10 mm) L5 (n = 11), 8.5 ± 0.8 mm (range 8–10 mm) S1 (n = 24), 10.8 ± 2.6 mm (range 8–17 mm) S2 (n = 28), 12.6 ± 6.2 mm (range 8–34 mm) S3 (n = 23) 14.5 ± 6.1 mm (range 8–35 mm), S4(n = 6), 14.3 ± 3.4 mm (range 10–20 mm)	• IENFD was < 5th percentile for age-sex in 82% • Nerve conduction abnormalities included delayed sural nerve response latency (6%, 1/16), low sural nerve amplitude (13%, 2/16) and delayed Hoffman reflexes (25%, 5/20) • Anal reflexes were delayed in 95% (20/21) and 57% (12/21) patients with delayed anal reflex latency reported mild (48%) to severe (10%) fecal incontinence • EMG during voluntary contraction showed patchy neurogenic motor unit potentials of mild severity mainly at the L5 (72%, 13/18), (82%, 18/22) and S3–S4 (82%, 18/22) myotomes • EMG abnormalities of myotomes generally did not correspond to cyst location

Author, year, country

Referral cohort, investigations

Tarlov cyst details

Presenting symptoms

Langdown [37]

2005

Australia

• 54-patient cohort (38 women, 16 men) mean age 54.4 years (range 27–83 years) with symptom duration months to years

• Referred over a 5-year span for a spinal surgeon specialist opinion for low back pain, sciatica or spinal stenosis

• All cysts occurred in the sacral region

• Cysts were frequently multiple in various locations, unilateral, central or bilateral

• Low back pain (n = 30), nerve root pain (n = 17), leg pain (n = 9), and neurological loss (n = 5)

Marino [73]

2013

Italy

• 157-patient cohort (138 women, 19 men) mean age 48 ± 11 years with a mean age at symptom onset at 42 years of age

• Between October 2008 and May 2012 referred to a neurosurgical outpatient clinic

• Underwent neurological investigations (complete electroneurography of lower limbs), bowel/bladder and gynecological exams

• Pain scored by VAS and depression by the Hamilton Depression Rating Scale

• Cases involved single or bilateral sacral cysts

• Lumbar cysts (n = 3)

• Almost all with perineal or lower back pain

• MRI evidence lumbar and/or sacral disc herniation (95%)

• Sphincter disorders (34.4%) similar for women and men)

• Sexual dysfunctions higher for men vs women (36.8% vs 28.2%)

• Electroneurographic findings (n = 32) were normal

• Pain mean VAS score 4.7 ± 2.0 and depression rating scale 18.1 ± 10.4 in the mild severity range (similar for men and women)

• Social psychological effects included mood disorders, social, employment issues and loss of jobs

Murphy [74]

2016

Canada

• 213-patient cohort, 289 cysts

• Between 2003 and 2012 referred to an interventional neuroradiologist and spine neurosurgeon

• Underwent lumbar and dedicated sacral MRI, physical exam, neurological assessment and/or gynecologist or urologist evaluation if pelvic, abdominal or genital symptoms were present

• Pain and function assessed by Lumbar Spine Outcomes Questionnaire

• Cysts involved single nerve roots unilaterally (n = 113), single roots bilaterally (n = 78) and more than two roots bilaterally (n = 22)

• Location mainly S2 (n = 142) and S3 (n = 120) sacral levels

• Cyst size ranged between 2 and 4 cm (n = 143), 8 cysts were greater than 4 cm

• Generalized sacral and/or lumbar pain (89%)

• Pelvic pain and/or perineal pain (98%)

• Bladder (43%), bowel (29%)

• Sexual dysfunctions (43%)

• Common neurologic abnormalities included absent Achilles reflex (61%), plantar flexion weakness (41%), reduced rectal sphincter tone (29%), bladder sphincter impairment (43%), cyst-related sensory loss at S1 (8%), S2 (64%), S3, S4, S5 (46%)

Baker [71]

2018

United States

• 65-women cohort, mean age 53 ± 12 years, 89% White

• Between July 2004 and October 2015 referred to urogynecology or neurosurgery clinics

• Indication for clinic visit, back pain, radicular pain, pelvic pain, sexual dysfunction urinary or bowel dysfunction

• Medical and surgical history, physical exam detection of lower extremity numbness or weakness and urodynamic testing

• Sacral cysts mainly located at the S2 or S2/S3 sacral regions

• Cyst mean size 17 mm (range 5– 59 mm)

• Sacral cysts larger than 10 mm (90%)

• Symptoms by region: lumbosacral (95%), urinary (78%), bowel (55%), central nervous system (40%) and sexual dysfunction (25%)

• Commonly reported low back pain (83%), lower extremity pain (75%), positional pain arising to sitting or standing (62%), urinary urgency (54%) and urinary frequency ((48%)

• Urodynamic testing (n = 40) with 78% having abnormalities with early bladder filling sensation the most frequent finding

• Urinary urge incontinence (31%) vs 7% general population

Hulens [72]

2018

United States

• 33-patient cohort (30 women, 3 men) mean age 49.8 years

• Study data collected July 2015 and October 2016

• Comparator group, 42 age-sex matched patients (38 women, 4 men) experiencing long-term back pain or sciatica due to degenerative disorders or inflammatory disease

• Nerve conduction tests and electromyography for lumbar and sacral nerve root myotomes

• Symptom profiles based on modified International Tarlov Cyst Questionnaire (Feigenbaum 2022)

• Study restricted to Tarlov cysts ≥ 15 mm in diameter

• Symptomatic for mean 9.5 years and were significantly more common in patients with Tarlov cysts vs those with only back pain

• Lower limbs [foot pain (24% vs 10%), leg pain (25% vs 5%), foot paresthesia (31% vs 5%), and subjective leg weakness (72% vs 28%)]

• Pelvic symptoms [perineal paresthesia (24% vs 5%) dyspareunia (32% vs 5%), and coccygodynia (49% vs 17%)]

• Bowel and sphincter [constipation (63% vs 33%), anal pain (57% vs 10%), mild fecal incontinence (55% vs 7%)]

• Bladder and urinary sphincter: hesitation (38% vs 5%), retention (55% vs 17%), and frequency (69% vs 38%)

• Pain aggravating features sitting (100% vs 74%) or long walks (75% vs 34%)

• Reduced social functioning (78% vs 18%), forced to stop working (54% vs 18%)

Lim [42]

2020

United States

• 39-patient cohort (34 women, 5 men) mean age 51.3 years (range 24–83 years)

• Between January 2010 and November 2012 referred to an academic chronic pain center having MRI-identified Tarlov cysts and pudendal neuralgia (validated by Nantes criteria), a chronic pelvic pain syndrome

• Cysts mainly located at S2–S3 sacral level (64%)

• One cyst outside the pudendal nerve distribution (L5-S1)

• Cyst sizes 44% small (< 1 cm), 50% moderate (1–2 cm)

• Pain locations for women in the perineum (n = 7), rectum (n = 14), and vagina (n = 19) and for men in the perineum (n = 4) penis (glans) (n = 2) and scrotum (n = 3)

• Comorbid conditions for women including interstitial cystitis (n = 4), pelvic floor tension myalgia (n = 17) and pelvic organ prolapse (n = 7), persistent genial arousal disorder (PGAD) (n = 2)

• Pelvic floor tension myalgia in men (n = 2)

Cattaneo [83] 2001

Italy

• 11-patient cohort referred to an outpatient EMG laboratory with lumbosacral MRI documented sacral Tarlov cysts

• Sural nerve investigated electrophysiologically

• In 5 patients with sural nerve abnormalities, cysts size ranged from 2 to 3 cm, were located bilaterally (n = 3), or unilateral right (n = 2) and at the S1 to S3 sacral levels

• Symptoms included sciatica (n = 3), bilateral foot paresthesia and pain (n = 1) and 1 was asymptomatic

• Sural sensory abnormalities found in five patients (2 women, 3 men) aged 40 to 66 years

• Abnormalities were localized to the side of the Tarlov cysts and the size of the cyst was not related to the presence and extent of the nerve damage

• Motor nerve conduction was spared demonstrated with normal findings in all subjects accounted for by the location of the cysts at the dorsal root

Hulens [84]

2016

Belgium

• 3 case reports (3 women)

• Sural nerve conduction studies and electromyelographic tests evaluating nerve injury and relating to patients’ symptoms

• Multiple Tarlov cysts ranging in size from 6 to 36 mm

• Symptoms included radicular back leg pain, urinary/fecal sphincter disturbances, perineal pain, dyspareunia, and headaches

• EMG findings varied in patients with delayed sural nerve response and ano-anal reflex occurring

Hulens [85] 2017

Belgium

• 30-patient cohort (27 women, 3 men) with Tarlov cysts mean age 46 years (range 25–74 years)

• Referred to a physical medicine outpatient clinic for unexplained refractory low back, pelvic, perineal and/or leg pain, symptomatic for mean 11.6 ± 12.0 years (range 8 months and 50 years)

• Needle EMG studies to evaluate lumbosacral dermatomes

• Cysts located on L5 to S4 nerve roots were commonly bilateral with a mean size of 7.1 mm (range 3 to 36 mm)

• Nerve root dilations or smaller Tarlov cysts (< 10 mm) were found in the cervical (C7) to thoracic (TH4) regions for most (23/30) patients

• Symptoms included pain in lower back/sacral pain (83.3%), buttock (80%), coccygeal 47%, perineal 33%, dyspareunia/genital pain (69%); parasthesis in perineum (47%), buttocks (47%), legs (63%), foot/feet (80%) – foot drop (3.3%); bladder dysfunction (77%), bowel dysfunction (70%)

• Increased pain with sitting (96.7%) or standing (86.7%)

• Sural nerve conduction abnormalities (16.7%) with 4 of the 5 dermatomal abnormalities corresponded to dermatomal pain and/or paresthesia

• S1 Hoffman-reflex latency abnormality (23.3%) with 7/7 corresponding to dermatomal pain and/or paresthesia

• Ano-anal reflex abnormality (89.3%) with 23/25 corresponding to dermatomal pain and/or paresthesia

• Needle EMG abnormalities were found at all levels: L4 (36.7%), L5 (76.7%), S1 (40%), S2 (96.6%), and S3–S4 (75%), with abnormalities corresponding to Tarlov cysts on that nerve root: L4 (7/18), L5 (33/49), S1 (25/58), S2 (32/56), and S3-S4 (37/59)

Hulens [86]

2022

Belgium

• 31 patients (26 women, 5 men) mean age 47 ± 10 years (range 31–74 years) with symptomatic Tarlov cysts larger than 8 mm

• Lumbar and sacral nerve root abnormalities investigated for large- and small-fiber neuropathy

• Investigations included EDX tests (n = 24) included nerve conduction and needle EMG, and lower leg skin biopsies to assess IENFD (n = 17), 11 patients underwent both IENFD and EDX

• Cysts located mainly in the sacral areas varied in mean size:

L4 (n = 3), 8.7 ± 1.2 mm (range 8–10 mm)

L5 (n = 11), 8.5 ± 0.8 mm (range 8–10 mm)

S1 (n = 24), 10.8 ± 2.6 mm (range 8–17 mm)

S2 (n = 28), 12.6 ± 6.2 mm (range 8–34 mm)

S3 (n = 23) 14.5 ± 6.1 mm (range 8–35 mm), S4(n = 6), 14.3 ± 3.4 mm (range 10–20 mm)

• IENFD was < 5th percentile for age-sex in 82%

• Nerve conduction abnormalities included delayed sural nerve response latency (6%, 1/16), low sural nerve amplitude (13%, 2/16) and delayed Hoffman reflexes (25%, 5/20)

• Anal reflexes were delayed in 95% (20/21) and 57% (12/21) patients with delayed anal reflex latency reported mild (48%) to severe (10%) fecal incontinence

• EMG during voluntary contraction showed patchy neurogenic motor unit potentials of mild severity mainly at the L5 (72%, 13/18), (82%, 18/22) and S3–S4 (82%, 18/22) myotomes

• EMG abnormalities of myotomes generally did not correspond to cyst location

EDX electrodiagnostic studies, IENFD intraepidermal nerve fiber density