Table 3. Diagnosis of neuropathic pain and inclusion criteria.

Reference	Dx of NP		Inclusion criteria
Abrams, et al. 2007 [63]	(1) Adults with HIV infection and symptomatic HIV-SN (2) Painful HIV-SN was confirmed by symptoms of symmetric distal pain or dysesthesias in the lower extremities for at least 2 weeks, combined with absent or depressed ankle reflexes or sensory loss of vibration, pin, temperature, or touch on examination by the study neurologist.		(1) Average daily pain score of at least 30 mm on the 100 mm VAS during the outpatient pre-intervention phase. (2) Patients were in stable health. (3) Without current substance abuse (including tobacco) (4) Followed a stable medication regimen for pain and HIV for at least 8 weeks prior to enrollment, (5) All patients were required to have prior experience smoking cannabis.
Almog, et al. 2020 [47]	The diagnoses of NP and CRPS were made by an investigating physician according to IASP 2008 [64], and Budapest criteria [67], respectively.		(1) Adult patients (18 years of age or above), (2) Suffering from chronic pain with a baseline pain intensity of 6 or above on a 10-cm visual analog scale (VAS), (3) Licensed by the Israeli Ministry of Health to receive cannabis-based medications. (4) Active users had to agree to abstain from cannabis-based medications 12 hr. before study intervention. (5) Women of fertile age had to declare using contraception.
Berman, et al. 2004 [49]	(1) At least one avulsed brachial plexus injury (2) at least 18 months duration		(1) Men/women 18 + (2) Stable pain pattern 4 + weeks (3) Stable medication regimen 4 + weeks and during study (4) No cannabis use at least 7 days prior to study
Eibach, et al. 2020	The diagnosis of HIV-associated sensory neuropathy was confirmed by a clinician based on: ∙ patient history, ∙ the Douleur Neuropathique 4 interview (DN4i) [40] ∙ the Clinical HIV-associated Neuropathy Tool [68].		(1) 18 - 65 years old (2) Pain > 4 on a NRS (0 - 10)
Ellis, et al. 2009 [56]	(1) HIV-DSPN diagnosed by a board-certified clinical neurologist included: ∙ the presence of abnormal bilateral physical findings (reduced distal tendon reflexes, distal sensory loss) or ∙ electrophysiological abnormalities (distal leg sensory nerve conduction studies), ∙ symptoms of pain and paresthesia, acquired in the setting of HIcV infection. (2) NP refractory to a least two previous analgesics		(1) Average score of 5 or higher on the pain intensity subscale.
Karst, et al. 2003 [57]	Presentation and examination consistent with hyperalgesia and allodynia. Diagnoses included: ∙ NP of the left arm and right arm due to traumatic cervicobrachial plexus lesions ∙ Neuropathic facial pain due to traumatic lesions of the left maxillary nerve, left trigeminal nerve, and mental nerve bilaterally. ∙ NP behind the left ear due to traumatic lesion of the left great auricular nerve. ∙ NP of the left forearm and hand due to traumatic lesion of the left radial nerve ∙ NP in the left leg and right leg due to lumbar disk protrusion or intraspinal scar tissue after lumbar disk surgery ∙ Pain in one or both legs due to traumatic spinal cord lesions ∙ NP of the sole of the left foot due to compression of the tibial nerve (tarsal tunnel syndrome) ∙ Neuropathic whole-body pain below the shoulders due to tethered cord syndrome after surgical removal of an intrathecal ependymoma ∙ Neuropathic left facial pain (n = 1) of unknown cause.		(1) Stable levels of pain medications for at least 2 months, (2) Age 18 to 65 years, (3) Concomitant pain-relieving medications allowed were antipyretic and opioid analgesics, flupirtine, anticonvulsants, and antidepressants. (4) Pain for at least 6 months.
Nurmikko, et al. 2007 [58]	(1) Unilateral peripheral NP and allodynia (2) Demonstrate mechanical allodynia and impaired sensation within the territory of affected nerve(s) on clinical examination. (3) Patients with CRPS were eligible if they showed evidence of peripheral nerve lesion (diagnosed as CRPS type II)		(1) Age 18 or over, male or female (2) A history of at least 6 months duration of pain due to a clinically identifiable nerve lesion (3) A baseline severity score of at least 4 on the numerical rating scale for spontaneous pain for at least 4 of 7 days in the baseline week (4) A stable medication regimen of analgesics for at least 2 weeks prior to study entry
Selvarajah, et al. 2010 [50]	Patients with chronic painful diabetic peripheral neuropathy (Neuropathy Total Symptom Score 6 [66] >4 and <16)		(1) At least 6 months of pain (2) Stable glycemic control (HbA1C <11%) (3) Those with persistent pain, despite an adequate trial of tricyclic antidepressants, were recruited.
Serpell, et al. 2013 [61]	(1) Had mechanical allodynia within the territory of the affected nerve(s) confirmed by either a positive response to stroking the allodynic area with a brush or to force applied by a monofilament. (2) At least one of the following underlying conditions, which caused their Peripheral NP: ∙ post-herpetic neuralgia, ∙ peripheral neuropathy, ∙ focal nerve lesion, ∙ radiculopathy or ∙ CRPS type 2.		(1) Aged 18 or older, (2) At least a 6-month history of PNP and were receiving the appropriate treatment for their PNP. (3) Patients also had a sum score of at least 24 on a pain 0–10 NRS for more than 6 days (baseline days 2–7) and pain that was not wholly relieved by their current therapy. (4) Analgesic regimen was stable for at least 2 weeks preceding study entry.
Svendsen, et al. 2004 [51]	(1) Diagnosis of multiple sclerosis (clinical definite multiple sclerosis and laboratory supported definite multiple sclerosis), (2) Assessed central pain after a clinical examination by a doctor. The criterion for central pain was:		(1) Age between 18 and 55 years, (2) Central pain at the maximal pain site with a pain intensity score ≥3 on a 0-10 numerical rating scale. (3) We allowed concurrent spasm related pain if the patient was able to distinguish spasm related pain and central pain. (4) We allowed additional pain outside the maximal pain site if pain intensity was low and distinguishable from the central pain
Wade, et al. 2002 [60]	(1) Eligible patients had to have a neurological diagnosis and to be able to identify troublesome symptoms which were stable and unresponsive to standard treatments. (2) NP pain associated with muscle spasm and tremor and included multiple sclerosis (n=18), spinal cord injury (n = 4), brachial plexus damage (n=1), and limb amputation (n = 1)
Wallace, et al. 2015 [52]	(1) Diabetes mellitus type 1 or type 2, who had stable glycemia (HbA1c ≤11%) and were maintained by diet or a stable regimen of diabetic therapy for at least 12 weeks before the evaluation. (2) Presence of both spontaneous and evoked pain in the feet, (3) At least a six-month history of painful diabetic peripheral neuropathy diagnosed according to research diagnostic criteria (using the Michigan Neuropathy Screening Instrument [69]), which included:		(1) Participants were men and women. (2) Age 18 or older
Ware, et al. 2010 [62]	(1) NP of at least three months in duration caused by trauma or surgery, with allodynia or hyperalgesia, (2) Average weekly pain intensity scores greater than 4 on a 10-cm visual analogue scale.		(1) Men and women aged 18 years or older. (2) Participants had a stable analgesic regimen and reported not having used cannabis during the year before the study. (3) normal liver function normal renal function, normal hematocrit and a negative result on human chorionic gonadotropin pregnancy test (if applicable).
Wilsey, et al. 2008 [53]	(1) Patients with CRPS type I, spinal cord injury, peripheral neuropathy, or nerve injury. (2) The specific historic and physical findings included burning pain, skin sensitivity to light touching or cold, skin color changes, swelling, limited movement of the affected body part, motor neglect or abnormalities in skin temperature, hair growth, nail growth, and/or sweating.		(1) Previous cannabis exposure was required of all participants. (2) Refrain from smoking cannabis or taking oral synthetic delta-9-THC medications for 30 days before study sessions to reduce residual effects; each participant underwent urine toxicology screening to confirm this provision.
Wilsey, et al. 2013 [54]	NP disorder: (1) CRPS type I, formerly known as reflex sympathetic dystrophy. (2) thalamic pain, (3) spinal cord injury, (4) peripheral neuropathy, (5) radiculopathy, or (6) nerve injury		(1) Required to refrain from smoking cannabis or taking oral synthetic THC medications for 30 days before study sessions to reduce residual effects; each participant underwent urine toxicology screening to confirm this provision as much as was feasible. (2) Previous cannabis exposure (3) No depression.
Wilsey, et al. 2016b (exploratory) [55]	Individuals with injury and disease of the spinal cord		(1) Age >18 and <70 yrs. (2) Pain intensity >4 on a scale of 10
Wilsey, et al. 2016a (preliminary) [59]	NP as defined by Leeds Assessment of Neuropathic Symptoms and Signs [107]		(1) 18-70 yrs. (2) Pain intensity of 4/10.

Abbreviations: CRPS, complex regional pain syndrome; Dx, diagnosis; HbA1C, glycated hemoglobin; HIV-DSPN, human immunodeficiency virus associated distal sensory predominant polyneuropathy HIV-SN, human immunodeficiency virus associated sensory neuropathy, hr, hour; NP, neuropathic pain; NRS, numeral rating scale; PNP, peripheral neuropathic pain; THC, tetrahydrocannabinol; VAS, visual analog scale; yrs, years.